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CIRP ANNALS 2002

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STC A

Automated Assembly of Mechatronic Products

G. Reinhart (2), T. Angerer

STC A, 51/1/2002, P.1

Keywords: Assembly, Automation, Mechatronic System

Abstract : The synergetic combination of mechanical engineering, electrical engineering, electronics and information technology enables mechatronic products to offer high levels of flexibility and performance. This interdisciplinary interaction requires changes in product structure and accordingly adapted in production strategies. The approach outlined in this article shows the specific use of the product structure with a view to increasing assembly efficiency. The product is actively integrated in the assembly process by setting up an IT link and making use of its sensor/actuator equipment and software, thus providing support for the production system. This makes it possible to increase the efficiency of automation while at the same time reducing assembly costs.

Automated Calibration of Robot Coordinates for Reconfigurable Assembly Systems

T. Arai (1), Y. Maeda, H. Kikuchi, M. Sugi

STC A, 51/1/2002, P.5

Keywords: Assembly, Calibration, Robot

Abstract : To achieve higher reconfigurability of an assembly line, quick plug-in and plug-out of devices such as robots is essential. When a new device is installed into the assembly line, calibration should be made. This research deals with an automated calibration system of relative position/orientation based on the Direct Linear Transformation method using two CCD cameras. The cameras are freely positioned, and then a set of motions is commanded to each manipulator. By detecting the motion with the cameras, the relative position of the two robots is obtained. The resultant accuracy is 0.16 mm rms at the best.

Bottleneck Analysis of Assembly Lines with Characteristic Curves

H.-P. Wiendahl (1), M. Hegenscheidt

STC A, 51/1/2002, P.15

Keywords: assembly systems, simulation, operating curves

Abstract : Tuning the performance parameters of all stations of interlinked manufacturing and assembly systems to ensure the planned capacity is a major challenge. The application of system simulation for this task is little common, particularly in SMEs. A suitable tool for quickly assessing the specific influence of a standalone station on the entire system performance has been developed on the basis of the characteristic curve theory. The applied methodology and the results obtained are presented in this paper.

Mode-based Decomposition of Part Form Error by Discrete-Cosine-Transform with Implementation to Assembly and Stamping System with Compliant Parts

W. Huang, D. Ceglarek (2)

STC A, 51/1/2002, P.21

Keywords: Form error, Geometric tolerancing, Discrete cosine transformation

Abstract : A discrete-cosine-transformation (DCT) based decomposition method is proposed for modeling part form error, which decomposes the error field into a series of independent error modes. Compression, which ensures a compact model, is achieved by correlation reduction or mode truncation based on good energy compaction property of DCT. The part error related to assembly process (rigid body modes) and part distortion during manufacturing (deformation modes) can be separated and identified. DCT has been proven to be equivalent to least square regression with 2D cosine-base for modeling of part variation pattern. Estimation of these parameters in the model has also been developed. The proposed method was applied to model and evaluate assembly and stamping errors at one of the US stamping plant.

Strategies to Optimize the Part Transport in Crossbar Transfer Presses

H. Hoffmann (1), M. Kohnhäuser

STC A, 51/1/2002, P.27

Keywords: Computer aided manufacturing (CAM), Production, Transfer Press

Abstract : In order to keep the production of wide body components profitable, even in high-wage countries, the technology of crossbar transfer presses has been implemented into the stamping plants of automobile companies. In particular with large compliant parts, dynamic problems during the transportation have to be seen as one of the limiting factors for the production stroke rate. So far, there are no tools to investigate these problems in order to optimize the material handling. Based on the interaction of different simulation systems, a solution has been developed to predict these problems as early as during the construction process of a die. It becomes possible to calculate the ideal positions for the part holding suction-cups and to analyze the dynamic behavior of the stamping part during transportation, in order to enhance the productivity of the production plant. The results of the generic methodology have been verified by experimental research on compliant sheet metal parts of automotive industry.

Platform for the Integration of Assembly, Disassembly and Life Cycle Management

E. Westkämper (1)

STC A, 51/1/2002, P.33

Keywords: Assembly, Integration, Life Cycle Management

Abstract : Information- and communication technologies as they are available by Internet can be used for the management of products life cycle. In the future it will be possible to link all technical products to the Internet and to supervise their life with economic and environmental aspects. Behind of the development of Internet there are theories like the agent theory and standards like XML, which allow the realization and efficient usage of flexible open networks to optimize each products technical usage. Assembly and disassembly are main processes in the life cycle, which finalize products and ensure their utilization. Taking into account the development of modular intelligent products there are new sustainable strategies for manufacturers. They need platforms to manage products and to add value in the after sales processes. This paper includes a definition of an overall platform for life Cycle management based on Internet and agent theories. It focuses on aspects of assembly and LCM of high quality capital goods like assembly systems.

Platform for the Integration of Assembly, Disassembly and Life Cycle Management

E. Westkämper (1)

STC A, 51/1/2002, P.33

Keywords: Assembly, Integration, Life Cycle Management

Innovative Processes and Tools for Disassembly

G. Seliger (2), B. Basdere, T. Keil, U. Rebafka

STC A, 51/1/2002, P.37

Keywords: Disassembly Processes, Disassembly Tools, Product Accompanying Information Systems

Abstract : Cycle economy as a paradigm for industry in the 21st century depends on economical and ecological treatment of limited resources. The objective is to achieve more use with fewer resources. Adaptation processes including disassembly and re-assembly contribute significantly towards this objective. The usual disassembly of used products is characterized by a high rate of manual operations. The number of upcoming used products varies strongly. The goods which have to be disassembled have unknown product properties and a great variety of product types. To cope with such demands, modular disassembly processes and tools are developed. These are implemented in a integrated disassembly cell using product accompanying information systems for the control.

A Model for Improving Economic Performance of a Demanufacturing System for Reduced Product End-of-Life Environmental Impact

J.W. Sutherland, K.L. Gunter / K.J. Weinmann (1)

STC A, 51/1/2002, P.45

Keywords: Disassembly, Environmental, Simulation

Abstract : A demanufacturing facility benefits the environment by removing end-of-life products from the disposal waste stream. The facility dismantles end-of-life products and then places salvaged components into inventory for subsequent sale to remanufacturers and other firms. Lack of profitability will cause a demanufacturing facility to abandon its mission, with the environment suffering as a result. A model is presented for a demanufacturing facility that describes the disassembly process activities, the accumulation of component inventories, component sale based on market price behavior, and inventory management costs. The effect of three selling policies on financial performance is investigated. Selling policy is seen to be the dominant factor in determining profitability, with transaction and holding costs also influencing the performance.

Methodological Approach and Reconfiguration Tool for Assembly Systems

E. Travaini, p. Pedrazzoli, R. Rinaldi, C. R. Boër (1)

STC A, 51/1/2002, P.9

Keywords: Assembly, System, Reconfiguration

Abstract : Assembly lines design is intended to solve many problems related to assembly operations. The introduction of a new product should often entail the salvage of existing assembly lines. This work proposes a methodology for assembly line reconfiguration, to rationalize and support the redesign process of assembly systems. This research formalizes a representation model and a method for assembly line reconfiguration. The model describes the main characteristics and significant features of the assembly process. The study is concerned with three fundamental models, the first describes assembly line structures. The second illustrates component assembly features and the third produces all the assembly sequences. The assembly line reconfiguration method provides an analysis and estimation tool on the reconfiguration process complexity. The method proposed is also meant to be a tool to identify the operational flexibility limit. It is an interactive method, driven and controlled by the reconfiguration model. The method results point out the way to implement assembly system reconfiguration. When the method suggests that the reconfiguration process is possible, it gives detailed information about the assembly line. Each assembly line, facing a new product to be assembled, is processed with the reconfiguration method and receives operative results for reconfiguration process and quality indicators. Complete information are retuned either in successful and in unsuccessful case by the reconfiguration method.

Process safeguarding throughout the product life cycle

H. Bley (2), P. Braun, N. Fischer

STC A, 51/1/2002, P.41

Keywords: Life Cycle, Quality Assurance, Hardening

Abstract : Measurement technologies are mandatory in different manufacturing technologies and can be found in all phases of the product life cycle. Often there are a lot of parameters that influence process quality. The limita-tions of sensor-based measuring methods with which quality-affecting quantities can be detected are also un-known. Therefore, quality loops are needed to react to imperfections at an early stage and to minimize the re-ject rate. A large, up to now incompletely examined field is the influence of surface contaminations on subsequent processes such as adhesive bonding, coating, soldering, welding, hardening, etc.. As an example the paper will concentrate on a hardening process succeeding a machining process.

Function-based assembly: an application of MEMS-based assembly of rate gyroscopes

Z. Shvets, E. Zussman (2)

STC A, 51/1/2002, P.331

Keywords: Assembly, Micro-electromechanical systems, optimization

Abstract : The assembly of MEMS-based devices in certain applications requires alignment within tolerances better than 1m. This standard has proven to be difficult to achieve consistently due to manufacturing and assembly errors. This article describes an active alignment process which incorporates the actual geometric parameters of the microelements as well as geometric constraints in order to determine the optimal location of the microelements in the assembly. The determination of this location guarantees optimal functionality of the device and helps achieve tight alignment tolerances without compromising the device design. The effectiveness of this approach is demonstrated in a micromachined vibrating rate gyroscope assembly. Simulation and measurements taken of the assembled rate gyroscope confirmed an assembly accuracy of better than +/- 1µm.

STC C

Wear Behavior of CVD-Diamond Tools

E. Uhlmann (2), M. Brücher

STC C, 51/1/2002, P.49

Keywords: Cutting, Diamond coating, Wear

Abstract : Diamond cutting tools are often the only choice for the machining of high-strength and highly abrasive non-ferrous alloys. During machining, a complex interaction of different wear mechanisms takes place on the tools. This interaction considerably hinders a purposeful detection of specific wear mechanisms. Therefore, the objective is to systematically analyze the wear processes that occur when machining a hypereutectic aluminum silicon alloy with CVD-diamond tools. The main wear mechanisms are identified and the limits for the use of various CVD-diamond tools are indicated. The findings gained will serve in the further development of these high-performance cutting materials.

Wear Mechanism when Machining Compacted Graphite Iron

E. Abele, A. Sahm, H. Schulz (1)

STC C, 51/1/2002, P.53

Keywords: Cast iron, Machinability, Tool wear

Abstract : The industrial application of compacted graphite iron in the automotive industry is taking a rather long time due to its uneconomic machinability, because of a significant decrease in tool life. After six years of holistic research of the PTW in cooperation with foundries, manufactures and material scientists, the wear mechanism was understood and clarified: Sulphur in the microstructure of compacted graphite iron has direct influence on the formation of a manganese-sulphur layer on the cutting edge. For machining gray cast iron this layer protects the cutting edge against abrasive wear. Therefore the design of cutting tools for the machining of CGI must consider the absence of manganese-sulphur layer.

Effect of Tool Wear on Roughness in Hard Turning

M.L. Penalva, M. Arizmendi, F. Díaz, J. Fernández / Z. Katz (1)

STC C, 51/1/2002, P.57

Keywords: Hard Turning, Roughness, Tool Wear

Abstract : This paper attempts to make a contribution to wear estimation of CBN tools when turning hardened steels. It is well known that cutting edge geometry deteriorates with wear. Although many authors have considered tool wear process has a random nature, detailed tool examination has proved that wear has some deterministic features in these processes. Thus, plastic deformation exists in the early stages while gradual abrasion makes the cutting edge recede. On the other hand, it has also been found that there is a good replication of the tool on the roughness profile. Therefore, cutting edge state might be predicted with reasonable accuracy through roughness parameters. This strategy allows fast tool wear estimation by simple roughness measurements using a shop floor instrument.

Effect of the Cutting Edge Radius and its Manufacturing Procedure, on the Milling Performance of PVD Coated Cemented Carbide Inserts

K.-D. Bouzakis (1), N. Michailidis, G. Skordaris, S. Kombogiannis, S. Hadjiyiannis, K. Efstathiou, G

STC C, 51/1/2002, P.61

Keywords: Cutting, PVD coating, Edge radius, Milling

Abstract : The fatigue and wear behaviour of PVD coatings on cemented carbide inserts with various cutting edge radii are investigated experimentally and analytically in milling. The inserts with cutting edge radii from 8 up to 35 µm were manufactured by honing and micro-blasting. The tool wear progress was depicted through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) microspectral analysis. The Finite Elements Method (FEM) simulation of the contact between the tool and the workpiece highlights the effect of the cutting edge radius on the first coating fracture and the further wear development. The wear behaviour of the cutting edge radii manufactured by honing, in comparison to the corresponding ones by means of micro-blasting, is significantly enhanced, whereas the cutting edge radius increasing can lead to a higher tool life.

Chip Formation, Acoustic Emission and Surface White Layers in Hard Machining

J. Barry, G. Byrne (1)

STC C, 51/1/2002, P.65

Keywords: Chip formation, Acoustic emission, Surface white layer

Abstract : In hard machining, sawtooth chip formation is due to initiation of adiabatic shear within the lower region of the primary shear zone. Catastrophic failure within the upper region of the shear zone occurs through either of two different mechanisms and results in the rapid release of elastic strain energy. This periodic release of strain energy is the dominant source of acoustic emission during sawtooth chip formation. In addition to adiabatic shearing in the primary and secondary shear zones, there is evidence to suggest that it occurs in the tertiary shear zone also; namely the surface white layer.

Microstructure-Mechanics Interactions in Modeling Chip Segmentation during Titanium Machining

R. Shivpuri (2), J. Hua, p. Mittal, A.K. Srivastava / G.D. Lahoti (1)

STC C, 51/1/2002, P.71

Keywords: Cutting, Chip, Microstructure

Abstract : Chip segmentation in machining of titanium alloys is strongly influenced by the microstructural state of the material. A numerical model is presented that incorporates material changes into the phenomenological behavior of the chip. It is calibrated by comparing results with experimental measurements at different cutting speeds and feeds. It predicts that at lower cutting speeds fracture propagates in the ??? phase towards the cutting tool face resulting in a discontinuous chip. At higher cutting speeds, temperature in the secondary shear zone reaches ? transus increasing material ductility; the fracture propagates towards the outer surface resulting in a continuous but segmented chip.Chip segmentation in machining of titanium alloys is strongly influenced by the microstructural state of the material. A numerical model is presented that incorporates material changes into the phenomenological behavior of the chip. It is calibrated by comparing results with experimental measurements at different cutting speeds and feeds. It predicts that at lower cutting speeds fracture propagates in the ??? phase towards the cutting tool face resulting in a discontinuous chip. At higher cutting speeds, temperature in the secondary shear zone reaches ? transus increasing material ductility; the fracture propagates towards the outer surface resulting in a continuous but segmented chip.

Predictive Cutting Models for the Forces and Torque in Machine Tapping with Straight Flute Taps

E.J.A. Armarego (1), M.N.P. Chen

STC C, 51/1/2002, P.75

Keywords: Metal Cutting, Tapping Operation, Predictive Force Models

Abstract : In this paper the development of predictive cutting models for the forces and torque in machine tapping operations with straight flute taps is outlined. The models, based on the ?Unified-Generalised Mechanics of Cutting Approach?, allow for the many tap and cut geometrical variables, the cutting speed and the toolcoating- workpiece material combinations. The models have been verified by extensive computer simulation studies as well as comprehensive experimental testing programmes. This investigation has provided a deeper understanding of the basic cutting action as well as predictive force models of tapping, renowned as ?one of the most neglected operation in machining research?.

A new Thermo-viscoplastic Material Model for Finite-Element-Analysis of the Chip Formation Process

G. Warnecke (2), J.-D. Oh

STC C, 51/1/2002, P.79

Keywords: Chip formation, Material model, Finite element method

Abstract : A new material model for describing the thermo-viscoplastic flow behavior of workpiece material in metal cutting is presented. In order to express the complex flow behavior which depends on the local strain, strain rate and temperature, a new methodology for sequential formulation is proposed. The material parameters which are achieved by using the flow stress data available at low strain rates are enhanced by matching the results of the experimental investigations and finite element simulations of the orthogonal cutting process. As a result, a material model which has a wide validity range of strain, strain rate and temperature is established.

An Analytical Predictive Model and Experimental Validation for Machining with Grooved Tools Incorporating Effects of Strains, Strain-rates, and Temperatures

N. Fang, I.S. Jawahir (1)

STC C, 51/1/2002, P.83

Keywords: Machining, Chip formation, Cutting force prediction

Abstract : By effectively integrating a recently developed universal slip-line model with Oxley's predictive machining theory, a new analytical predictive model for machining with restricted contact grooved tools has been developed and presented in this paper. A computational flow chart is provided to illustrate the method of integration. The cutting forces are predicted for varying flow stress properties to include the effects of strains, strain-rates, and temperatures. Extensive cutting tests involving the use of three groups of chip-grooves have been conducted to validate the new method. An encouraging good agreement has been found between predicted and experimental results.

Drilling of Multi-Layer Composite Materials consisting of Carbon Fiber Reinforced Plastics (CFRP), Titanium and Aluminum Alloys

E. Brinksmeier (1), R. Janssen

STC C, 51/1/2002, P.87

Keywords: Drilling, Titanium, Carbon Fiber Reinforced Plastics

Abstract : In this paper results are presented concerning the realization of economical drilling processes of multi-layer materials. Different carbide drill designs with improved geometries and coatings were investigated and compared by characterizing the cutting forces, tool wear, hole quality, and chip formation. Investigations have shown that dry machining of titanium workpiece layers leads to increased tool wear, chip formation problems, and surface damage in the aluminum and CFRP-layers. Consequently, the drilling experiments were carried out with minimum quantity lubrication (MQL) using different cutting fluids and supply strategies. The investigations were mainly focused on the development of the optimum drilling condition with respect to tool shape, tool material, and machining parameters. Another objective of the investigations was to analyze surface defects of the hole and the resulting diameter tolerances due to the high mechanical and thermal loads when machining titanium.

A Synthetic Ester as an Optimal Cutting Fluid for Minimal Quantity Lubrication Machining

S. Suda, H. Yokota, I. Inasaki (1), T. Wakabayashi

STC C, 51/1/2002, P.95

Keywords: Cutting, Fluids, Environment

Abstract : Significant progress has been made in dry and semidry machining recently, and minimal quantity lubrication (MQL) machining in particular has been accepted as a successful semidry application because of its environmentally friendly characteristics. A number of studies have shown that MQL machining can show satisfactory performance in practical machining operations. However, there has been little investigation of the cutting fluids to be used in MQL machining. In this study, several fluids, including vegetable and synthetic esters, are compared on the basis of the physical properties that would be suitable for MQL applications. The cutting performance of fluids is also evaluated using actual MQL operations. As a result, biodegradable synthetic esters are found to be optimal cutting fluids for MQL machining.

Skiving for high-performance machining of periodic structures

D. Spath (2), A. Hühsam

STC C, 51/1/2002, P.91

Keywords: Gear Cutting, Tool Design, Process Simulation

Abstract : Skiving is a continuous cutting method for high-performance machining of periodic structures. With this method, the main manufacturing times can be reduced substantially. The key to the successful application of skiving is the design of suitable tools and safe processes. Due to the complexity of the skiving kinematics, the tool design has to be based on simulation. A suitable software program was developed for this purpose, so that the complete shape of skiving tools can be defined. By simulating the production process with the same program, all cutting parameters for an optimum process adjustment can be determined. Furthermore, a geometric assessment of the resulting workpiece geometry is provided by the software program. The possibilities offered by the simulation software developed, and the skiving manufacturing method, are demonstrated by the example of cylindrical external gearing.

Ultrasonic Vibration Drilling of Microholes in Glass

K. Egashira, K. Mizutani / T. Nagao (1)

STC C, 51/1/2002, P.339

Keywords: Ultrasonic vibration cutting, Microhole, Glass

Abstract : Microholes with a diameter of 10 µm were drilled in glass by ultrasonic vibration cutting using a microtool fabricated by wire electrodischarge grinding. The workpiece was vibrated in order to realize high-precision tool rotation. Cutting was performed in the ductile regime at a depth of cut of 0.05 µm, leaving neither fractures nor cracks around the rim of the hole. The application of ultrasonic vibrations resulted in (1) a decrease in the required cutting force, (2) an extension of the tool life, (3) an increase in the permissible penetration and tool length and (4) smoother machined surfaces.

Manufacture of Multiple-focus Micro Fresnel Lenses by Means of Nonrotational Diamond Grooving

Y. Takeuchi (1), S. Maeda, T. Kawai, K. Sawada

STC C, 51/1/2002, P.343

Keywords: Ultra-precision, Micro-grooving, Fresnel lens

Abstract : The study deals with the manufacture of multiple-focus micro Fresnel lenses by means of nonrotational diamond cutting tools mounted on a 5-axis control ultraprecision machining center with the positioning accuracy of 1 nm and the rotational one of 0.00001 degree. Multiple-focus micro Fresnel lens, consisting of several micro Fresnel lenses, is not rotationally symmetric, thus requiring the introduction of 5-axis control ultraprecision machining center. Two-focus and three-focus micro Fresnel lenses are designed and manufactured by controlling the movement of nonrotational diamond cutting edge along the designed microgrooves at the cutting speed of 40 mm/min. As a result, the nonrotational diamond cutting method allows multiple-focus micro Fresnel lenses to be manufactured accurately and neatly without any burr generation.

Prevention of Exit Crack in Micro Drilling of Soda-Lime Glass

B.J. Park, Y.J. Choi, C.N. Chu (2)

STC C, 51/1/2002, P.347

Keywords: Drilling, Crack, Glass

Abstract : In micro drilling of glass plates, cracks occur at the exit surface. In this work, a back-up glass plate was used to prevent the exit crack. The mechanical lateral constraint was applied to the workpiece and the back-up glass plate to reduce tensile stress near the drill corner. In this way, crack-free holes could be produced. In order to avoid careful fixturing for the mechanical constraint, two glass plates were adhered with various liquids. It is shown that the liquid adhesion of the back-up glass plate without the mechanical constraint is a more effective method to prevent exit crack.

STC Dn

ULEO - Universal Linking of Engineering Objects

J.U. Zimmermann, S. Haasis, F.J.A.M. van Houten (1)

STC Dn, 51/1/2002, P.99

Keywords: Product development, information flow, automation

Abstract : This paper reports on ongoing research in the field of feature-based product development. The resulting ULEO approach aims at enabling a high-quality flow of information between applications and at universal automation of product model generation. This is achieved by modeling all classes of relevant objects within a Unified Model of Engineering Objects (UMEO). All types of relationships are modeled inside a dedicated meta taxonomy of relation types and materialize inside the UMEO. Informational relations represent ontological knowledge about dependencies between object classes and are suited for cross-linking of product models. Generative relations describe knowledge on how to create instances automatically.

Extendible Classification of Design and Manufacturing Features

O. Owodunni, D. Mladenov, S. Hinduja (2)

STC Dn, 51/1/2002, P.103

Keywords: Feature recognition, Feature classification, Feature library

Abstract : This paper discusses three different issues in feature classification. It proposes a complete taxonomy to cater for prismatic and rotational features which can be positive or negative. It also suggests a feature definition that makes it feasible for the feature library to be extendible without additional programming effort. A unique code is given to each feature so as to avoid redundancy and ensure consistency of labelling the feature faces. This labelling is achieved by a novel formalisation method based on a newly found graph? theoretical property of a B-rep model. Results for one of the several components investigated are included.

Simulation Within the Axiomatic Design Framework

J.W. Melvin, N.P. Suh (1)

STC Dn, 51/1/2002, P.107

Keywords: Axiomatic, Design, Simulation

Abstract : Creating systems with axiomatic design involves conception of physical embodiments and selection of design parameters to satisfy functional requirements at every level of the decomposition process. Simulation models characterize the system using accurate representations of system behavior, allowing the designer to make better decisions about which variables to use as design parameters, and best values for constants in the design. This paper describes a method of simulating designs created using axiomatic design so that the final system performance can be predicted. Simulation in tandem with axiomatic design allows the creation of systems with the best probability of satisfying the functional requirements.

An Axiomatic Approach for "Target Cascading" of Parametric Design of Engineering Systems

P. Ge, S.C.-Y. Lu (2), N.P. Suh (1)

STC Dn, 51/1/2002, P.111

Keywords: Design, System, Axiom

Abstract : Complex engineering system realization involves finding out design specifications that simultaneously achieve performance objectives at different levels. A common practice in industry is to adopt ?Target Cascading? to obtain proper settings of the performance objectives, and find out those design specifications, not necessarily optimal, but satisfying all the desirable component-level, subsystem-level and system-level performance objectives. In this paper, an Axiomatic Approach to ?Target Cascading? (AATC) is presented to improve the current ?Target Cascading? process. AATC uses axioms to guide the decompositions of performance objectives, and an integration of a hybrid meta-modeling tool and direct synthesis method to enhance both robustness and efficiency. The preliminary results of AATC's industrial applications demonstrate its advantage in improving productivity at the early stage parametric design, especially for complex engineering systems.

Axiomatic Design of Automotive Suspension Systems

S. Bae, J.M. Lee (1), C.N. Chu (2)

STC Dn, 51/1/2002, P.115

Keywords: Axiomatic Design, Kinematics, Suspension System

Abstract : This paper presents kinematic design methodology of a suspension system using Axiomatic Design (AD). AD is applied to typical three types of the front suspension systems: McPherson strut, double wishbone and multilink. Our study includes the analysis of the functional independencies of current suspension design configurations, which would add to the understanding of how various suspension hardpoints influence the suspension functional requirements (FRs). In addition, this paper also proposes sequential design orders in suspension kinematic design to satisfy all of the suspension FRs. Of the current kinematic designs, the multilink is a decoupled design, whereas McPherson strut and double wishbone are coupled designs. It is shown that a coupled design can be decoupled by applying the independence axiom. The design matrices formulated for the suspension systems indicate a specific design order to satisfy all FRs.

Working situation model for safety integration during design phase

A. Bernard (2), R. Hasan

STC Dn, 51/1/2002, P.119

Keywords: Design process, safety integration, experience feedback

Abstract : The fact that the design of equipment and machines can no longer be separated from the concept of human safety has led to the definition of criteria which is linked to the equipment's exploitation and must be taken into account during their design. Firstly, this paper looks at the problem of integrating safety into design as early as possible, reviews the state of the art and examines the research carried out on this subject to date. The area of application of our research is then presented. The production system analyzed is an offset printing line. We propose a system model by defining the working situation and the elements characterizing this situation as well as the concepts relative to these elements. The model is presented and the method is illustrated by the results of an experiment carried out in the design department of an industrial partner. The ultimate aim is to provide designers with the means of integrating information about the potential work context into the equipment's design process from the onset.

Economic Evaluation of Design-for-Test Alternatives for Microelectronics Products

Z. Wang, W.A. Knight (2)

STC Dn, 51/1/2002, P.123

Keywords: Integrated Circuit Design, Test, Cost Estimating

Abstract : Cost-of-Ownership (COO) models, developed for integrated circuit (IC) fabrication equipment, can be extended to the various cost domains of microelectronics design and development cycles. Details of a COO model developed to evaluate design for test (DFT) alternatives are given, together with the results of application to case studies of different test scenarios. Scan and Built-in-Self-Test (BIST) are popular DFT solutions. Mixed scan/BIST alternatives are shown to reduce overall costs through improved fault coverage, which justifies extra design overhead and slight performance degradation in most cases. For all but relatively simple IC products economic benefits from DFT solutions are demonstrated.

Decision-based process design for shortening the lead time for mold design and production

M. Nakao, S. Yamada, M. Kuwabara, M. Otubo, Y. Hatamura (1)

STC Dn, 51/1/2002, P.127

Keywords: Mold, Decision making, Design

Abstract : We propose ?Decision-based process design? for reducing the process time of the design and production of molds. This method reviews the human processes of making decisions for setting unknown parameters, and reduces their process time by actively reducing the operations with such decisions. We applied decisionbased process design to the design and production of injection molding cellular phone shells, together with 3D-CAD and high speed machining. The application reduced the number of decision operations to 77, 13%37; of the total number of operations, and drastically decreased the process time by 86%37; down to 50 hours.

Piecewise B-spline Surfaces Fitting to Arbitrary Triangle Meshes

L.Y. Zhang, R.R. Zhou, J.Y. Zhu (1), X. Wu

STC Dn, 51/1/2002, P.131

Keywords: Reverse engineering, Surface reconstruction, Spline

Abstract : Due to technical progress in shape acquiring from range data, triangle mesh representations of models can now be obtained conveniently. However, triangle meshes are not the final representation form in many applications, for reasons of compactness, appearance, modification, and manufacturability etc. In this paper, we present a solution for fitting smooth B-spline surfaces to triangle meshes of arbitrary topology. The procedure consists of two major phases: (1) partitioning triangle meshes of arbitrary topology into quadrilateral patches, (2) fitting tensor-product B-spline surfaces to each quadrilateral patch and keeping patches continuous across shared boundaries and corners. One merit of our solution is that it makes a reasonable tradeoff between automation and human control in complex model segmentation and surface fitting. Experiments in the paper show that our solution is practical and effective.

A computer system for tooth root optimization of case-hardened gearwheels

M. Weck (1), O. Brömsen

STC Dn, 51/1/2002, P.135

Keywords: Structural optimization, Hardened gear, Surface property

Abstract : Today, shape optimization methods allow the minimization of the maximum stress occurring in the tooth root under load. For homogeneous material characteristics, as they are found in quenched and tempered steel, this is expected to result in similar increases in load carrying capacity. Highly loaded gearwheels are frequently case-hardened to achieve depth-dependent strength gradients, increasing from the core to the surface. Furthermore, load-reducing compressive residual stresses are induced within the surface layer. For case-hardened components, the reduction in maximum stress does not necessarily lead to an equivalent increase in load carrying capacity. In order to directly maximize the load carrying capacity of a gearwheel instead of minimizing the load stresses a computer system is developed which considers local strength as well as residual stresses.

A rapid reverse engineering system for reproducing 3D human busts

H-Min Rho (2), Y. Jun, S. Park, H-R. Choi

STC Dn, 51/1/2002, P.139

Keywords: Reverse Engineering, Reconstruction, Polygons

Abstract : The most critical problems in the current reverse engineering (RE) are often related to data registration and hole filling. This is because no single scan image is sufficient to describe the entire object since most objects occlude themselves, and some scanned data is likely to be missing on the object. In this paper, we establish a registration and a hole-filling algorithm to solve this problem. The registration module is based upon the standard Iterative Closest Point (ICP) algorithm with some additional heuristics, which help to overcome the limitation of ICP requiring that one of the data scans must be a subset of the other. The aligned triangle mesh is still unsuitable for model reproduction since it often has missing data. The proposed hole filling algorithm reconstructs these missing data with the iterative manner and these data are then smoothed with their neighboring polygonal meshes. We have developed a dedicated system for reproducing a human head and shoulder by using the implemented polygon-based algorithms. The system quickly reconstructs the surface datails of human busts and produces the replica of 3D human model using 4-axis CNC milling machine. Some typical examples are presented to validate the system and further research work is also discussed.

Design of Micro-photonic Beam Steering Systems

S.-G. Kim (2), Y. Shi, Y. Jeon

STC Dn, 51/1/2002, P.335

Keywords: Optical, Piezoelectric, MEMS

Abstract : The paper introduces a direct photonic beam steering device, which is intended to be used as a large scale all optical switch array for communication networks. The objective is to direct the light beam with two degrees of freedom, so the beam from any of the input ports can be sent to any of the output ports, satisfying the optical and operation requirements. The technology is enabled through the integration of microelectromechanical systems, thin film piezo actuators, optical engineering technologies, and Axiomatic approach to systems design. The curved electrode electrostatic and thin film piezoelectric actuators are simulated in advance to the microfabrication processes. This technology has the potential of many novel applications such as: all optical switching, microendoscopy and gazable microeye among others.

STC E

An Experimental Investigation of Laser Cladding

G. Chryssolouris (1), S. Zannis, K. Tsirbas, C. Lalas

STC E, 51/1/2002, P.145

Keywords: Laser, cladding, experiments

Abstract : Laser cladding uses a laser beam to fuse materials with enhanced metallurgical properties on a substrate. A thin layer of the substrate is molten achieving good metallurgical bonding with the added material. In this paper experimental data from an industrial application of laser cladding are presented and discussed. The material of the substrate was an aluminum alloy and the cladding material was copper based powder. Under constant laser power and beam diameter, experiments were performed using various powder feed rates, process speeds and gas supply. The dimensions of the clad as well as the alloying and dilution depth were measured. The experimental data were analyzed in order to obtain a working range for the process parameters.

Thermal Stress Cleaving of Brittle Materials by Laser Beam

T. Ueda (2), K. Yamada , K. Oiso, A. Hosokawa

STC E, 51/1/2002, P.149

Keywords: Laser beam machining, Fracture, Temperature

Abstract : Abstract Thermal stress cleaving is a prospective technique for separating a wafer or thin plate from brittle materials such as glasses and ceramics. In this paper, the cleaving mechanism of a silicon wafer irradiated with Nd:YAG laser is investigated. A pulsed laser is used for the purpose of investigating the mechanism of crack propagation more precisely. The temperature at the area irradiated with the laser is measured using a two-color pyrometer with an optical fiber. The AE signal is also measured to examine the mechanism of the crack propagation. The AE signal makes it possible to monitor the crack behaviour. During one pulse of the laser, crack propagation begins some milliseconds after laser heating and ceases at about the end of irradiation. The temperature at the area irradiated with the laser is an important factor in the control of the propagation of the crack to achieve high cleaving accuracy and low thermal damage.

Hole Taper Characterisation and Control in Laser Percussion Drilling

L.Li, D.K.Y.Low, M.Ghoreshi / J.R. Crookall (1)

STC E, 51/1/2002, P.153

Keywords: Laser, drilling, quality

Abstract : Small hole (< 1 mm diameter) drilling by lasers is widely applied in various manufacturing processes. Hole tapering is one of the inherent manufacturing problems associated with laser percussion drilling (multiple pulse drilling) whereby material is ejected in the form of molten droplets when a series of laser pulses are delivered to a point on a workpiece. This paper reports an investigation into the mechanisms of hole taper formation, its characteristics and the development of a taper control technique. A statistical modelling technique is used to characterise the parameter relationships during hole-taper formation. Laser beam interpulse shaping is used to control the hole-taper. Parallel holes are produced as a result of this new development.

Real-time Tool Wear Compensation in Milling EDM

P. Bleys, J.-P. Kruth (1), B. Lauwers, A. Zryd, R. Delpretti, C. Tricarico

STC E, 51/1/2002, P.157

Keywords: Electrical discharge machining, Milling EDM, Tool wear compensation

Abstract : Accurate machining by milling EDM (i.e. CNC contouring EDM with a rotating cylindrical or tubular electrode) necessitates compensation of the tool electrode wear. Existing anticipated wear compensation is based on off-line tool wear simulation prior to machining. This can be combined with corrections based on periodical measurements of tool length during machining. Anticipated wear compensation involves an important restriction: an exact model of the blank geometry must be available in order to perform the tool wear simulation. This paper presents a new method of wear compensation. On-line estimation of tool wear is used for combining anticipated compensation with real-time compensation. This extends the scope of milling EDM to the machining of blanks of which the exact shape is not known in advance.

Some Considerations to Machining Characteristics of Insulating Ceramics-Towards Practical Use in Industry-

N. Mohri (2), Y. Fukuzawa, T. Tani, T. Sata (1)

STC E, 51/1/2002, P.161

Keywords: Electrical discharge machining, Electrode, Ceramics

Abstract : Machining of insulating ceramics can be realized in EDM by using the assisting electrode method. After a tool electrode cuts through the assisting electrode, a carbon layer covers the ceramics? surface during EDM. This carbon layer, formed from the decomposition of the hydrocarbon working oil, enhances the ceramics surface?s conductivity. In this paper, machining phenomena of insulating ceramics are considered towards practical use in industry. Several kinds of insulating ceramics and assisting electrode materials are investigated under considerations of various machining characteristics; and high speed machining in W-EDM is carried out under conditions of lower tension than usual.

High Precision Simulation of WEDM Using Parametric Programming

F. Han, M. Kunieda (2), T. Sendai, Y. Imai

STC E, 51/1/2002, P.165

Keywords: Wire EDM, Simulation, Parameters

Abstract : This paper describes the development of a simulation method for WEDM (Wire Electrical Discharge Machining) which can accurately reproduce the discharge phenomena of WEDM on computer. The simulation process consists of searching for discharge locations, removing the workpiece and analyzing wire vibration. Since unclarified parameters such as ignition delay time, explosive force, damping coefficient, and permittivity of dielectric in simulation are difficult to measure from experiments, they were obtained by solving the reverse problem using parametric programming. With the parametric programming method, optimum parameters for simulation are searched simultaneously to minimize differences between simulation results and experimental results.

A Finite Element Simulation of the Electroplating Process

E.S. Masuku, A.R. Mileham, H. Hardisty, A.N. Bramley (1), C. Johal, p. Detassis

STC E, 51/1/2002, P.169

Keywords: Electroplating, FEM, modelling

Abstract : This paper describes the development, comparison and validation of both 2-D and 3-D models of the electroplating process in which the current density distribution, generated using the Finite Element Method (FEM), is used together with Faraday's law of electrolysis to determine the local plating depth. Prior to work on industrial components, a preliminary investigation was undertaken on the electroplating of a square copper cathode (work piece) with a parallel lead anode of identical shape. The results described here show good agreement, particularly in 3-D and are considered to validate the model sufficiently for it to be used for electroplating tooling design.

Nanocrystalline Electroforming Process

D. Zhu (2), W.N. Lei, N.S. Qu, H.Y. Xu

STC E, 51/1/2002, P.173

Keywords: Deposition, Nano-grain, Electroforming

Abstract : This study focuses on nanocrystalline electroforming for the improvement of the properties of deposited parts in precision and micro fabrications. Experiments were conducted to refine the grain size and understand the effects of the grain size on properties of deposited metals. It has been found that high frequency pulse current, strong electrolyte flushing and some additive significantly refined the crystal grain and reduced average sizes of grains down to 20nm. The reduction of grain sizes has been found to offer substantial gains in the properties of the deposited metal such as the hardness and the corrosion resistance.

Precision high temperature lead-free solder interconnections by means of high-energy droplet deposition techniques

P.P. Conway, E.K.Y. Fu, K. Williams / D.J. Williams (1)

STC E, 51/1/2002, P.177

Keywords: Metal deposition, Welding, Lead free soldering

Abstract : This paper presents a number of numerical models that illustrate the experimental details of the key physical phenomena affecting the operation of novel materials deposition processes for electronics assembly. These processes include both laser and electric arc based droplet deposition processes. These are being developed in the electronics industry to allow the use of new lead-free alloys as replacements for high temperature lead based alloys, such as Sn5Pb95. The paper presents models of physical processes with respect to the desired process metrics of droplet size and deposition accuracy and reviews the potential limiting product - process interactions such as excessive thermal excursions and their effects on the target materials being joined.

Fabrication of Biomedical Prototypes with Locally Controlled Properties Using FDM

P. Gu (2), L. Li

STC E, 51/1/2002, P.181

Keywords: Rapid prototyping, composites, biomedical structure

Abstract : Biomedical structures have complex geometries and mechanical behaviors, and are difficult to manufacture using traditional machining processes. This paper reports a study of fabrication of biomedical structures using fused deposition modelling (FDM) processes. The theoretical and experimental analyses of mechanical behaviours of FDM prototypes were carried out to establish the constitutive models. A new set of equations is proposed to calculate the elastic constants of FDM structures as functions of the constituent properties and geometric characteristics, taking into account of imperfect bonding among filaments and void geometries. The manufacturing parameters of deposition orientation and density are modeled for fabrication of prototypes with functionally graded properties. Examples are included to illustrate the fabrication of bone structures with locally controlled properties.

EDM-Lathe for Micromachining

T. Masuzawa (1), K. Okajima, T. Taguchi, M. Fujino

STC E, 51/1/2002, P.355

Keywords: Micromachining, Micro-EDM, Micro-boring

Abstract : In this paper a new type of micro-EDM machine is proposed. The machine operates similarly to a turning lathe. An electrode fabrication system is installed which makes it possible to fabricate on-the-machine complex microelectrodes with sharp edges and corners. A prototype set of equipment was realized and test machining proved that a machine of this type can produce microcylindrical, overhung cavities, or cylindrical microholes with larger internal diameters than the entrance diameter. This result reveals the possibility of fabrication of various microparts such as microball bearings.

High Aspect Ratio and Complex Shaped Blind Micro Holes by Micro EDM

Z.Y. Yu, K.P. Rajurkar (1), H. Shen

STC E, 51/1/2002, P.359

Keywords: Micro-machining, EDM, Performance

Abstract : It is difficult to drill high aspect ratio through holes and complex shaped blind holes using micro EDM. The debris concentration in the narrow discharge gap causes abnormal discharges leading to excessive electrode wear and lower machining precision. In micro EDM, the electrode size is too small for internal flushing. This paper presents a new approach for effective self-flushing using planetary movement. Through micro holes with an aspect ratio of 18 have been drilled. This approach is also demonstrated by drilling blind noncircular micro holes with sharp corners and edges. The process performance characteristics are analyzed under different machining conditions.

STC F

Analysis of the levelling process based upon an analytic forming model

E. Doege(1), R. Menz, S. Huinink

STC F, 51/1/2002, P.191

Keywords: levelling process, elastic-plastic bending, analytic forming model

Abstract : Roller levelling is a complex forming process to minimize flatness imperfections and residual stresses by repeated forming of a sheet. At the Institute for Metal Forming and Metal Forming Machine Tools at the University of Hanover an analytic forming model is being developed which analyses the levelling process with sufficient precision in a shorter time than is possible with the finite element method (FEM). With this analytic forming model, the states of multiple forming under bending conditions during the levelling process can be investigated. The residual stresses and the residual bend of the sheet metal are calculated. Additionally, the forces acting on the rollers during levelling are determined. The controlling system assures setting of rollers automatically.

Flexible Sheet Forming Technology by Double-sided Simultaneous Shot Peen Forming

R. Kopp (2), J. Schulz

STC F, 51/1/2002, P.195

Keywords: Forming, Shot peening, Finite element method (FEM)

Abstract : The exceptionally flexible forming technology shot peen forming is used primarily on large, threedimensionally curved sheet metal in the aircraft and aerospace industries. Depending on the kinetic shot energy, both convex and concave curvatures will be generated. The most recent development, doublesided simultaneous shot peen forming, brings about a higher productivity of the entire process. FEM simulations of single and multiple impacts are presented in order to evaluate the characteristics of concave curvatures generated by both single and double-sided peen forming.

Analysis of Material Formability in Incremental Forming

L. Filice, L. Fratini, F. Micari (2)

STC F, 51/1/2002, P.199

Keywords: Forming, Sheet, Incremental

Abstract : Incremental forming is an innovative sheet metal forming technology in which a blank is plastically deformed through the progressive action of a small-size punch, whose movement is governed by a CNC machine. In this way the tool locally deforms the material through an almost pure stretching deformation mechanics. The paper is focused on material formability in incremental forming. Several tests were developed, aimed to the achievement of different straining conditions in the material and consequently to the determination of Forming Limit Diagrams for progressive forming operations. The features and the application of such FLD are discussed in the paper.

Process layout avoiding reverse drawing wrinkles in hydroforming of sheet metal

F. Vollertsen / K. Lange (1)

STC F, 51/1/2002, P.203

Keywords: Sheet metal forming, hydro forming, modelling of wrinkling

Abstract : Sheet metal forming processes like the fluid form process or hydromechanical deep drawing have the potential for the manufacture of parts having high precision, large drawing ratio, and low costs especially for small and medium lot sizes. In deep drawing using a separating membrane between the liquid and the sheet the process layout for drawing of complex parts must avoid not only the typical failures of bottom fracture, first and second order wrinkles, but also an additional type of wrinkles which are maybe created at the beginning of the process. The development of these wrinkles is described using an analytical model, which was validated by experimental results. The model was used to develop the process layout for deep drawing of a complex sheet metal part.

Combined Methods for the Prediction of Dynamic Instabilities in Sheet Metal Spinning

M. Kleiner (2), R. Göbel, H. Kantz, C. Klimmek, W. Homberg

STC F, 51/1/2002, P.209

Keywords: Sheet metal spinning, Wrinkling, Predictive process analysis

Abstract : A technological and mathematical understanding of the sheet metal spinning process allows to predict dynamic instabilities which lead to wrinkling and other defects in the workpiece depending on the axial feed of the roller tool, the design and the number of the forming passes as well as the angular velocity of the workpiece. The development and combined application of methods of statistical design of experiments, nonlinear time series analysis and finite element analysis yields insight into the dominant effects. The results will allow to predict wrinkling and to design and control the process as to avoid it. Preventing workpiece damage by wrinkling, this methods will help to significantly improve process efficiency.

Experimental evaluation and FE simulation of thermal conditions at tool surface during cooling and deformation phases in hot forging operations

P.F. Bariani (1), G. Berti, T. Dal Negro, S. Masiero

STC F, 51/1/2002, P.219

Keywords: Hot forging, Tool, Heat transfer

Abstract : In hot and warm forging operations, surface layers of tools at the tool-workpiece interface are not only exposed to high mechanical stresses but also to severe temperature cycles, which often lead to loss of strength and hardness and thermal fatigue failure as well. This paper offers an approach for determining heat transfer conditions at the surface of punches and dies during both the deformation and the cooling-lubrication phases of forging cycles. The approach is based on temperature readings inside the tool, FE simulation and inverse analysis. An application case is illustrated where operating conditions reproduce hot forging of turbine airfoil sections.

Lubrication and Friction of Magnesium Alloys in Warm Forging

R. Matsumoto, K. Osakada (1)

STC F, 51/1/2002, P.223

Keywords: Forging, Friction, Magnesium alloy

Abstract : In order to realize precision forging of magnesium alloys, the frictional behavior of ZK60 (Mg?6%37;Zn?0.5%37;Zr) is studied. At room temperature, the friction test of ZK60 sliding over the surfaces of cemented carbide tool with and without TiC+TiCN+TiN and DLC (diamond like carbon) coating is carried out. It is found that the DLC coated film is effective to reduce the coefficient of friction and the oxide film of magnesium increases friction. For warm forging, ring compression tests are carried out at temperatures from 200 °C to 300 °C. Several liquid lubricants are applied onto the tool surfaces by controlling the film thickness and the effect of lubrication on friction is examined. Some methods for heating and lubrication for warm forging of magnesium alloys are suggested.

Mechanical Properties of Ultrafine Grained Steel Produced by Repetitive Cold Side Extrusion

A. Azushima (2), K. Aoki

STC F, 51/1/2002, P.227

Keywords: Extrusion, Steel, Strength

Abstract : Ultrafine grained microstructure was produced by repetitive deformation using the cold side-extrusion method from carbon steels. The side-extrusions with lateral pressure were repeated up to 10 passes without rotation. Each sample was uniformly deformed by the side-extrusion, and the equivalent strain was 1.15 after a single pass of the side-extrusion. After 10 passes of side-extrusion an ultrafine grained steel with a tensile strength of over 1000MPa a grain size of 0.5µm x 0.2 µm was developed for the ultra low carbon steel. The uniform elongation in tensile test for the steels after repetitive side extrusions was very small, but the cold formability was very good. By the heat treatment, the uniform elongation became larger.

Excimer Laser Micro Texturing of Cold Forging Tool Surfaces - Influence on Tool Life

M. Geiger (1), U. Popp, U. Engel

STC F, 51/1/2002, P.231

Keywords: Tribology, Excimer Laser, Surface

Abstract : In bulk metal forming the tribological state is significantly dependent on the surface topography of tool and workpiece. To provide the process with an improved tribological behaviour in some cases the billet?s surface is prepared by shot blasting. Micro texturing of the tool surface provides an additional opportunity to optimise the frictional conditions. This paper deals with the investigation of micro texturing of the surface of TiN-coated tools with regard to their tribological behaviour in the field of cold forging. The micro textures are applied by excimer laser radiation. Tool life investigations in an industrial press shop yield that the tool surface can be improved significantly leading to higher tool life.

Analysis of Pick-Up development in Punching

D.D. Olsson, N. Bay (1), J.L. Andreasen

STC F, 51/1/2002, P.185

Keywords: Punching/blanking, Tribology, Lubrication

Abstract : The development of pick-up of work piece material on the punch surface with increasing number of strokes during punching of stainless steel sheet is investigated applying Scanning Electron Microscopy (SEM), 3D roughness mapping and measurements of the backstroke force. It is found that pick-up on the punch stem develops gradually backwards from the tip of the punch with increasing number of strokes saturating at a certain level while the radial build-up in the case of dry friction conditions continues until the clearance between the punch and die has been filled up. The rate of pick-up is significantly smaller in case of lubrication and may be very low if an efficient boundary lubricant is applied. Good correlation between the pick-up development and the backstroke force is found.

Hydromechanical Deep-Drawing of Aluminium-Alloys at Elevated Temperatures

P. Groche, R. Huber, J. Dörr, D. Schmoeckel (1)

STC F, 51/1/2002, P.215

Keywords: Hydromechanical Deep-Drawing, Warm Forming, Material Properties

Abstract : This paper presents a technology that combines the different effects used in hydromechanical and warm deep drawing to reduce the drawing force and to increase the transmittable drawing force in the deep drawing process of aluminium sheets by flange heating and by using a counter pressure. Adequate process parameters and an optimised tool design are discussed in thermo-mechanically coupled Finite Element Simulations. The required system parameters, such as temperature and strain rate dependent flow curves, temperature dependent friction coefficients and heat transfer coefficients, were detected in different model experiments for the numerical simulations. Experimental results are presented to highlight the possibilities and limitations of this forming method.

STC G

Assessment of Grinding Fluid Effectiveness in Continuous-Dress Creep Feed Grinding

J. Webster (2), E. Brinksmeier (1), C. Heinzel, M. Wittmann, K. Thoens

STC G, 51/1/2002, P.235

Keywords: Grinding, Grinding Fluid, Surface Integrity

Abstract : Creep feed grinding is a high-productivity abrasive removal process that is often limited by thermal damage and high wheel wear. A review of current industrial practices in the area of fluid supply optimisation in grinding shows that very little knowledge of the pressure, flowrate and method of application exists in industry. This paper presents an experimental procedure to evaluate fluid supply conditions in grinding on a continuous-dress creep feed grinder. Using tapered workpieces, the authors have evaluated the influence of wheel speed and material removal rate on grinding fluid effectiveness, based on the material removal rate at the position of the wheel along the ramp when burn starts to occur and the corresponding spindle power surge. Correlations are investigated between visible discoloration, metallurgical examinations and change in spindle power, in order to establish the onset of grinding burn. This procedure serves to determine the upper limit of material removal rate or - respectively - the lower limit of fluid flow rate for given grinding systems consisting of specified wheel type, material type, fluid type and fluid supply nozzle. The advantage of the presented method is its easy and time saving application in industry, but it is also of help to researchers who need to optimise fluid supply conditions prior to their grinding tests.

High Efficiency Deep Grinding of a Low Alloy Steel with Plated CBN Wheels

D.J. Stephenson (2), T. Jin, J. Corbett (1)

STC G, 51/1/2002, P.241

Keywords: Grinding, HEDG, Temperature

Abstract : High efficiency deep grinding (HEDG) of a low alloy steel (51CrV4) has been carried out on an Edgetek 5-axis CNC grinding machine, using electroplated CBN wheels. The initial tests were conducted in a surface grinding mode over a wide range of grinding conditions, to evaluate the levels of specific grinding energy, workpiece surface integrity and wheel wear. The burn threshold conditions for the ground workpiece surface have been proposed in terms of a critical heat flux which is shown to vary with material removal rate. Cylindrical grinding in HEDG mode has also been carried out based on the knowledge obtained from the surface grinding. It has shown that the HEDG technology can be transferred successfully to the field of cylindrical grinding to achieve very high specific material removal rates in excess of 400mm3/mm.s. The successful application of HEDG to cylindrical components depends on the appropriate selection of grinding parameters and also the grinding fluid supply strategy. Thermal modelling of the HEDG process combined with surface integrity studies, has shown that under cylindrical grinding conditions a significant reduction in grinding fluid supply is possible even when operating within the HEDG regime.

Micro-Analysis of the Contact Zone of Tribologically Loaded Second-Phase Reinforced Sol-Gel-Abrasives

F. Klocke (1), R. Engelhorn, J. Mayer, T. Weirich

STC G, 51/1/2002, P.245

Keywords: Grinding, Abrasives, Wear

Abstract : Abrasives manufactured via the Sol-Gel route have increased the grinding efficiency of conventional abrasive grinding tools to a remarkable degree in the past ten years. Little is known, however, about detailed wear mechanisms of the abrasive on a nanometer scale. Sliding tests on a pin-on-disk tribometer and single grit scratching tests have therefore been performed in order to identify the wear mechanisms of these innovative materials. TEM-analysis has revealed that severe plastic deformation combined with both crack bridging and crack deflecting effects in the second phase characterise the abrasive rim zone. The surface of the abrasive is covered with an oxide debris layer which substantially improves the tribological behaviour.

Microgrinding of Nanostructured Material Coatings

B. Zhang (2), X. Liu, C.A. Brown (2), T.S. Bergstrom

STC G, 51/1/2002, P.251

Keywords: Microgrinding, Nanostructured material coating, Surface integrity

Abstract : This study is aimed at experimentally investigating the effect of microgrinding process on the surface finish, subsurface damage and residual stresses of thermally sprayed nanostructured WC/12Co (n- WC/12Co) and Al2O3/13TiO2 (n-Al2O3/13TiO2) coatings. The material removal mechanisms are discussed. Surface textures are measured with stylus profilometry, scanning electronic microscopy (SEM) and atomic force microscopy (AFM), and analyzed using conventional methods and scale-sensitive fractal analysis. Residual stresses are measured with glancing incident X-ray diffraction (GIXD) technique that is capable of providing the depth profiles of residual stresses. Investigated is also grinding damage to the coatings.

Proposal of New Polishing Technology without Using a Polishing Pad

Y. Lu, Y. Tani (2), K. Kawata

STC G, 51/1/2002, P.255

Keywords: Polishing, Mirror finishing, Polymer particle

Abstract : A polishing method that uses no polishing pad is proposed, in which fine polymer particles are supplied together with abrasives onto a hard tool plate. The polymer particles prevent direct contact between workpiece and tool plate and serve as countless micro pads rubbing the abrasives against the workpiece for polishing action, so that not only slurry supply to and removal of polishing by-products from the workplate gap are kept good and constant, but also excessive frictional resistance may be suppressed. Polishing experiments with silicon wafers have shown that the method is feasible and characterized with higher material removal rates and less polishing resistance than conventional polishing.

Grinding of Si3N4 Ceramic Balls with the Aid of Photo-Catalyst of TiO2

Bo Zhang, A. Nakajima / M. Kiuchi (1)

STC G, 51/1/2002, P.259

Keywords: Dressing, Ceramics, Photo-Catalyst

Abstract : There are big needs from industry that the polishing process using loose abrasive be replaced by grinding process. This paper explores the possibility of replacement by investigating effects of the free radical reaction on the precision grinding performance. Free radicals were generated with the aid of TiO2, a kind of photo-catalyst. Experiments were conducted on Si3N4 ceramic ball grinding with a metal bonded diamond wheel of SD8000 and SD16000. It is found that, for SD8000, the material removal rate increases by a factor of about 6 when adding 7.5 wt%37; of TiO2 into grinding fluid. Ion exchanged water was used in this experiment. This increase in the material removal rate is expected to be due to the dressing effect of the free radicals of H O& and 2 O H in water, which are both very strong oxidizing agents. The free radicals of H O& and 2 O H are generated in the photocatalytic reaction process of TiO2 with water and oxygen under ultraviolet rays. For SD16000 only adding 1 wt%37; of TiO2 leads to a dramatic increase in material removal rate from 0.08 µm/hr to 0.55 µm/hr.

Modelling of high velocity, loose abrasive machining processes

A.M. Hoogstrate, B. Karpuschewski (2), C.A. van Luttervelt (1), H.J.J. Kals (1)

STC G, 51/1/2002, P.263

Keywords: Abrasive jet machining, Cutting parameter, Workpiece quality

Abstract : In the recent years the interest in loose abrasive machining processes as efficient, flexible processes is rising. This paper describes the development of a ?coherent set of models? for a category of these processes, namely those which use high velocity of the particles to obtain the necessary energy to machine a workpiece surface. The usability of this ?coherent set of models? will be explained with its application in the field of high-pressure abrasive waterjet cutting. At the end of this paper a forecast to the application of this modelling technique to other loose abrasive machining processes as Micro-Abrasive Air Jet Machining is given.

A New Method for Chatter Detection in Grinding

E. Govekar, A. Baus, J. Gradisek, F. Klocke (1), I. Grabec (1)

STC G, 51/1/2002, P.267

Keywords: Chatter, Monitoring, Grinding

Abstract : A new method for automatic chatter detection in outer-diameter grinding is proposed which exploits significant changes in grinding dynamics caused by the onset of chatter. The method is based on monitoring of a non-linear statistic called the coarse-grained entropy rate. The entropy rate is calculated from the fluctuations of the normal grinding force. Values of the entropy rate close to zero are typical of chatter, whereas larger values are typical of chatter-free grinding. If the entropy rate is normalized, a threshold value can be set which enables automatic distinction between chatter-free grinding and chatter.

High Efficiency Abrasive Tool for Honing

G. Burkhard, F. Rehsteiner (1) / B. Schumacher (1)

STC G, 51/1/2002, P.271

Keywords: Abrasive Tool, Honing, Defined Grain Formation

Abstract : Electroplated abrasive tools usually feature a high grain density, a limited grain protrusion and a stochastic grain distribution. These properties restrict the space for coolant supply as well as chip removal. A new technology has been developed to produce single layer abrasive tools in which the highly protruding grains are arranged in well defined patterns. This new method has been applied successfully to manufacture single stroke honing tools. Honing tests performed with these tools show a highly increased efficiency and a prolonged tool life. Compared with the state of the art they offer at least a tenfold tool life at twice the conventional feed rate.

STC M

Design Principles for Machining System Configurations

P. Spicer, Y. Koren (1), M. Shpitalni (1), D. Yip-Hoi

STC M, 51/1/2002, P.275

Keywords: Machining, system layout, design principles

Abstract : Until recently, mass producers have relied on long serial lines of dedicated machines in order to machine products at high volumes. Today, as the cost of CNC machining centers decreases, more and more highvolume manufacturers are examining the alternative of shorter lines with more machines configured in parallel. This paper presents the main principles for selecting the right machining system configurations. We propose a system classification and show that only symmetric configurations are of interest to industry. We compare four classes of systems: pure serial lines, pure parallel lines, short serial lines arranged in parallel, and short serial lines arranged in parallel with the ability to move products between the lines (i.e., with crossover). Specifically, we compare the different configurations in terms of throughput, line balancing, machine investment cost, and capacity scalability. Finally, we introduce an upgradable multi-spindle reconfigurable machine as a costeffective alternative for system scalability.

Structured Method for Identifying Success Factors in New Product Development of Machine Tools

H. Shinno (2), H. Hashizume

STC M, 51/1/2002, P.281

Keywords: Product development, Machine tools, Design methodology

Abstract : New product development of machine tools is always costly and risky for machine tools manufacturers; nevertheless, there have been few academic studies on the product development process of machine tools. Successful product developments were found to be related to perceived superior skills and resources within the objective of machine tools manufacturers. In this study, in order to establish the product development methodology for machine tools, the success factors in new product development have been identified based on the results of the interview and questionnaire investigations with experienced engineers in Japanese machine tools manufacturers. Based on the findings of this study, a structured method for identifying the success factors in new product development has been proposed.

Composite Machine Tool Structures for High Speed Milling Machines

J.D. Suh, D.G. Lee / R. Kegg (1)

STC M, 51/1/2002, P.285

Keywords: Machine structure, Composite, High Speed Machining

Abstract : To maximize the productivity in machining molds and dies, machine tools should operate at high speeds. However, the productivity of mold manufacturing has not increased significantly because CNC milling machines have massive slides, which do not allow rapid acceleration and deceleration during the frequent starts/stops encountered in machining molds and dies. This paper presents the use of composites for these slides to overcome this limitation. The vertical and horizontal slides of a large CNC machine were constructed by bonding high-modulus carbon-fiber epoxy composite sandwiches to welded steel structures using adhesives. These composite structures reduced the weight of the vertical and horizontal slides by 34%37; and 26%37;, respectively, and increased damping by 1.5 to 5.7 times without sacrificing the stiffness. Without much tuning, this machine had a positional accuracy of ± 5µm per 300 mm of the slide displacement.

Development of a Mixture Supply System for Machining with Minimal Quantity Lubrication

T. Aoyama (2)

STC M, 51/1/2002, P.289

Keywords: Environment, Machining, Spindle

Abstract : The minimal quantity lubrication (MQL) technique is used in cutting processes in order to reduce the environmental pollution caused by cooling lubricants. However, there can be problems with the MQL technique in high-speed machining. In high-speed machining, a spindle-through coolant supply method can effectively supply an oil mist to the cutting area. However, the centrifugal force from the high-speed rotation of the spindle causes the oil mist to separate. As a result, there is a decrease in the oil mist supplied to the cutting area. In this study, a new oil-mist supply mechanism was developed and installed in a high-speed spindle system. The performance of this proposed mechanism was evaluated by numerical simulation and an actual cutting test.

New Approaches to Machine Structures to Overcome the Limits of Classical Parallel Structures

R. Neugebauer (2), M. Schwaar, S. Ihlenfeldt, G. Pritschow (1), C. Eppler , T. Garber

STC M, 51/1/2002, P.293

Keywords: Parallel kinematic machines, Improvement, Limitations

Abstract : The day-to-day use of parallel kinematic machines (PKM) is limited by the size of their five-dimensional working area and position-dependent features. With the conventional hexapod, a structure optimisation does not offer the possibility of overcoming these problems. Three new approaches to machine structures for surmounting these limits are described and evaluated.

A Unified Error Model for Tolerance Design, Assembly and Error Compensation of 3-DOF Parallel Kinematic Machines with Parallelogram Struts

T. Huang (2), D.J. Whitehouse (1), D.G. Chetwynd

STC M, 51/1/2002, P.297

Keywords: Parallel kinematic machine, Error modeling, Assembly

Abstract : This paper presents a unified geometric error model that enables the tolerance design, assembly and calibration of a class of 3-DOF parallel kinematic machines with parallelogram struts to be integrated into a comprehensive framework. The error mapping function is formulated with a goal that enables the source errors affecting the uncompensatable pose error to be found. This is followed by the investigation into the influences of source errors on the pose accuracy with the aid of sensitivity analysis. The assembly process that enables to effectively reduce the uncompensatable pose error is also proposed.

A Piezo Tool Actuator for Precision Turning of Hardened Shafts

Y. Altintas (1), A. Woronko

STC M, 51/1/2002, P.303

Keywords: Piezoelectric actuator, Precision design, Hard turning

Abstract : A piezo actuator based fast tool servo is presented for precision turning of cylindrical shafts. The monolithic actuator housing transmits motion to the tool assembly using solid flexures. The actuator has a stroke of 36 m, 3200 Hz natural frequency, and 370 N/m stiffness. Two sets of additional piezo actuators are placed in the transverse direction to clamp the tool for increased stiffness during hard turning operations. A sliding mode controller rejects cutting forces and compensates the piezo stack nonlinearities. The tool position is controlled to within +/-10 nm during finish hard turning on a conventional CNC lathe.

Development of a Novel Modular and Agile Face Machining Technology

M.A. Elbestawi (1), S.C. Veldhuis, I.M. Deiab, M.J. Habel, C. Roberts

STC M, 51/1/2002, P.307

Keywords: Agile, Machine, Simulation

Abstract : A novel face machining technology has been achieved by combining milling and grinding into one operation. The system?s ability to control these distinct metal removal processes independently provides a high degree of process agility in terms of metal removal rate, surface finish and part flatness. A physics based model of the combined process has been developed to aid process development. It provides force and deflection values resulting from the unique excitation of milling and grinding together with the dynamics of the machine, fixture and part. The simulations are presently being validated using a prototype machine based on this machining technology.

Self-Excited Vibration Drilling Models and Experiments

S. Tichkiewitch (1), G. Moraru, D. Brun-Picard, A. Gouskov

STC M, 51/1/2002, P.311

Keywords: Vibration cutting, Modeling, Drilling

Abstract : A nonlinear dynamical model of vibration drilling is presented. It takes in consideration cutting interruption through surface generation equations. The linear stability analysis yields stability charts and the nature of Hopf bifurcation is discussed at critical values of cutting parameters. Dimensionless equations have been employed in order to obtain graphical charts that completely describe the dynamics of a pair of vibrationdrilling head ? workpiece material. The analysis of ?finite amplitude instability? phenomenon is carried out in time domain by computer simulations. A dynamic cutting fixture was used to run vibration drilling experiments. Based upon simulations and general vibration cutting model described here, the dispersion of the results from experimental work was explained. Important conclusions are drawn concerning forthcoming experiments in vibration drilling.

Real-Time NURBS Interpolator for Distributed Motion Control

B. Koninckx, H. Van Brussel (1)

STC M, 51/1/2002, P.315

Keywords: Distributed control, Real time interpolator, Numerical control (NC)

Abstract : Off-line toolpath planning for machine tools inevitably leads to suboptimal use of the given equipment and, even more important, excludes the possibility to accommodate for unforeseen or unmodelled effects. Online path planning however requires the availability of real-time interpolators which are both numerically efficient and deterministic and which do not depend on global information on the path to interpolate. Continuity of the interpolant up to higher derivatives is highly desirable. This paper presents an interpolation scheme that meets all these requirements. The algorithm generates a third-order, C2-continuous Non Uniform Rational B-Spline curve from a series of exactly interpolated position and velocity setpoints. This curve is at all instants completely determined from the first up to the last available setpoint. It is shown that a new setpoint affects only the last control points and the end of the knot vector of the interpolant. A graphical interpretation of the algorithm and a discussion on numerical issues and start conditions are presented.

Reliability Improvement of Industrial Robots by Optimizing Operation Plans Based on Deterioration Evaluation

A. Yamada, S. Takata (1)

STC M, 51/1/2002, P.319

Keywords: Reliability improvement, Deterioration evaluation, Operation plan

Abstract : This paper proposes a novel method for improving reliability of manufacturing facilities by optimizing operating conditions so as to reduce deterioration of critical components and to extend the life of facilities. The method is applied to an industrial robot. For deterioration evaluation, a life cycle simulation system has been developed. It evaluates wear of joint gears, which has critical effects on the accuracy of industrial robots. Optimization of operating conditions, defined in terms of layout of the robot and in motion pattern, is performed by means of a hybrid GA, which consists of genetic algorithm and simulated annealing. The effectiveness of the method has been verified by applying the method to assembly robots.

Development of Ultrasonic Elliptical Vibration Controller for Elliptical Vibration Cutting

E. Shamoto, N. Suzuki, T. Moriwaki (1), Y. Naoi

STC M, 51/1/2002, P.327

Keywords: Vibration control, Elliptical vibration cutting, Ultraprecision cutting

Abstract : A new ultrasonic vibration controller is elaborated for ultrasonic elliptical vibration cutting. A method is developed to remove cross talks between the two directional vibrations of the stepped vibrator excited in the same bending mode in two directions, so that the two directional vibrations can be controlled independently. A controller is fabricated to keep the elliptical vibration to have a desired locus, where the amplitudes of the two directional vibrations and their phase shift are kept to be desired values, and the vibration frequency is locked to an average value of their resonant frequencies. The developed vibration control system is applied to ultraprecision diamond turning of hardened die steel, and an ultraprecise mirror surface with a shape accuracy of less than 0.2 µm is obtained.

STC O

Resource-Aware Aggregate Planning for the Distributed Manufacturing Enterprise

P.G. Maropoulos (2), K.R. McKay, D.G. Bramall

STC O, 51/1/2002, P.363

Keywords: Computer automated process planning (CAPP), Distributed Design Manufacturing Integration

Abstract : The realization of ?intelligent and resource aware? distributed enterprises requires substantial development of the underpinning modelling, information management and knowledge representation technologies. This paper deals with the ?resource-aware, aggregate planning? of manufacturing operations at early design stages. The term ?resource aware? indicates the creation of a dynamic inter-relationship between the planning entities and the enterprise resources, humans and machines. The technologies employed for implementing the pilot methods include; a web-centric co-development environment, unique methods for enriching planning entities with knowledge, and a flexible engine supporting planning scenarios by using evolutionary computing for optimisation and capability analysis techniques for feedback evaluation.

Distributed Multiproject Resource Control: A Market-Based Approach

S.R.T. Kumara (1), Y.-H. Lee, K. Chatterjee

STC O, 51/1/2002, P.367

Keywords: Dynamic scheduling, Distributed project management, Project control

Abstract : The multiple project resource-scheduling problems extend job-shop scheduling problems by allowing for task dependency and multiple entities trying to maximize their own requirements fulfillment. In this paper we deal with decentralized scheduling of resources, which are shared by multiple projects. In specific, we address the dynamic nature of the situation. We model this as a virtual economy (entities as buyers and sellers of resources), where the ?resource-time slots? (resource availability over a given time) are traded as goods. Due to the dynamic and distributed nature of the economy, through our approach we achieve higher levels of flexibility and scalability. In this paper, we discuss our virtual economy model and the market mechanism along with empirical analysis and results.

Deadlock-free Rescheduling in Flexible Manufacturing Systems

H.A. ElMaraghy (1), T.Y. ElMekkawy

STC O, 51/1/2002, P.371

Keywords: Flexible manufacturing systems, Rescheduling and Time Petri Nets

Abstract : The dynamic nature of manufacturing makes rescheduling essential in today?s complex production environment, particularly in flexible and re-configurable systems. Research on optimizing schedules, that includes deadlock avoidance, is rather limited. Furthermore, the deadlock problem is mostly ignored in research on rescheduling. A rescheduling algorithm, that uses time Petri-Nets and the minimal siphons concept, was developed to deal with sources of disturbance such as machine breakdowns in real-time. It guarantees a deadlock-free new schedule. The existence of alternative routes, availability of material handling facilities, and the limitation of buffer capacities were taken into consideration. The developed algorithm modifies only the affected portion of the original schedule, rather than rescheduling all jobs, in order to limit changes to the original schedule and reduce the impact on the response time.

Modelling and Control of Production Systems based on Nonlinear Dynamics Theory

B. Scholz-Reiter (2), M. Freitag, A. Schmieder

STC O, 51/1/2002, P.375

Keywords: Production, Control, Nonlinear Dynamics

Abstract : Today's highly dynamic market with its rapid changing demand requires highly dynamic order processing in very flexible production systems. Most conventional production planning and control methods do not support such fast-moving activities. A dynamical approach is introduced for modelling and control of production systems. It was developed from concepts of the Nonlinear Dynamics Theory. Manufacturing processes as well as planning and control mechanisms are seen as one unit toward the establishment of a dynamical system. The dynamical approach includes an analysis of the dynamic behaviour of the production system as well as the control of the manufacturing process by a continuous adjustment because of changes or disturbances in the environment or in the production system itself.

Control-Theoretic Analysis of a Closed-Loop PPC System

N. Duffie (1), I. Falu

STC O, 51/1/2002, P.379

Keywords: Production, Control, Analysis

Abstract : An analysis of a production planning and control system with closed-loop control of backlog and work-inprogress is presented in this paper, illustrating integration of methods of control engineering with methods of production engineering. The architecture of the system is described and a control-theoretic dynamic model is developed that includes uncertainties in capacity and work input that result from equipment failures, rush orders, etc. Transfer function analysis is used to model dynamic relationships between system inputs and variables including backlog and work-in-progress. The results are used to select control laws for desired system performance and to calculate system response.

Logistical Positioning in a Turbulent Environment

H.-H. Wiendahl, N. Roth (2), E. Westkämper (1)

STC O, 51/1/2002, P.383

Keywords: Production planning and control (PPC), Design, Methodology

Abstract : To describe the new challenges for manufacturing companies in Production Planning and Control (PPC), the term ?turbulence? is increasingly used. An analysis of the difficulties in PPC shows the similarities to phenomena known from physics. The aim of this article is to describe these phenomena qualitatively and quantitatively and to exploit the resulting findings for the design of PPC and the logistical positioning.

Disassembly Scheduling with Capacity Constraints

D.-H. Lee, p. Xirouchakis, R. Züst (1)

STC O, 51/1/2002, P.387

Keywords: Disassembly scheduling, Optimization, Environment

Abstract : Disassembly scheduling is the problem of determining the ordering and disassembly schedule for used products while satisfying the demands of their individual parts or components over the planning horizon. The objective is to minimize the sum of purchase, inventory holding, and disassembly operation costs, subject to capacity restrictions in each period. In this paper, an integer programming model, which is a reversed form of the multi-level capacitated lot sizing problem, is suggested to represent and solve the problem optimally. A case study on used inkjet printers is worked out and the test results are reported.

Configuration of Manufacturing Cells for Dynamic Manufacturing

K.K.B Hon (1), F.J Lopez-Jaquez

STC O, 51/1/2002, P.391

Keywords: Group Technology, Cellular, Reconfigurable Manufacturing.

Abstract : Classical approach to the formation of manufacturing cells is based on the application of similarity principles to a binary machine-part matrix. This approach ignores volume effect as well as dynamic demand pattern. This paper first identifies and characterises the volume effect based on two measures of manufacturing cell efficiency, i.e., average job flow time and total intercell travelling time. The effect of similarity coefficient threshold value on cell configuration based on binary and volume data was evaluated and tested statistically. Finally, the implication of cell configuration on systems performance under dynamic demand pattern is discussed with an example based on 80 machines and 820 parts.

A new Fuzzy AHP method for the Evaluation of Automated Manufacturing Systems

M. Monitto, p. Pappalardo, T. Tolio (2)

STC O, 51/1/2002, P.395

Keywords: Automated Manufacturing Systems, Fuzzy Evaluation, Investment Decision Making

Abstract : The decision on production system acquisition for the automotive industry is very critical, given the number of different aspects to be considered. Indeed different automated solutions are feasible and evaluation techniques that take into account all the critical issues are needed to make a selection. In this paper a complete, precise and value driven Decision Support System is presented to support the selection of the best Automated Manufacturing System. The evaluation problem is solved using a Fuzzy Analytic Hierarchy Process (AHP) method able to manage uncertainty and to consider productivity and flexibility issues. Economic and financial performance and the effects on human resources due to the investment decision are also investigated.

Facility Layout Planning Using Self-Organization Method

K. Ueda (1), N. Fujii, I. Hatono, M. Kobayashi

STC O, 51/1/2002, P.399

Keywords: Manufacturing Systems, Layout Planning, Adaptive Systems

Abstract : This paper proposes a novel approach to facility layout planning based on the concept of biological manufacturing systems that deal with the inherent complexity of manufacturing using ideas of selforganization, evolution and learning. A self-organization method is proposed to generate facility layout plans autonomously according to the material flow which emerges from the local interactions among production elements. A case study of facility layout planning is presented for semiconductor manufacturing, in which it is difficult to find a proper layout because of complex process flow. The effectiveness of the proposed method is discussed in terms of the accumulated traveling distance of products and the throughput.

Distance Learning and Technology Transfer with Reality Transmission Capability

M. Mitsuishi (2), S. Warisawa, K. Tanaka

STC O, 51/1/2002, P.403

Keywords: Distance Learning System, Technology Transfer, In-Process Monitoring

Abstract : This paper discusses a distance learning system with reality transmission capability. Actual experience is crucial for education, in that much knowledge is obtained through the comparison of predictions with experimental results. Reality transmission capability allows real experiments to be performed in a distance learning system. Requirements for such a system are: (1) reality transmission capability, (2) bidirectional information transmission capability, and (3) independence of time and location. Experimental results are presented using a cutting simulator composed of a user interface to determine the cutting conditions, a stability lobe diagram and a display of cutting force, auditory and tactile information. A micro-machining experience system and a remote manufacturing system using a real time tracking vision system as an advanced user interface are also presented. Furthermore, a technology transfer experiment using the networked manufacturing system with reality transmission capability is discussed.

Integrated Virtual Manufacturing Systems for Process Optimisation and Monitoring

L. Chen (2), P. Bender, p. Renton, T. El-Wardany

STC O, 51/1/2002, P.409

Keywords: Virtual Manufacturing, Monitoring, Planning Tool

Abstract : The implementation of an Internet-based Virtual Manufacturing facility for the development and optimisation of new manufacturing processes is presented. The facility integrates advanced process simulation software, a remote machine monitoring system and multimedia technologies to realise a virtual environment for manufacturing process optimisation. Utilising physics-based process simulations, process parameters and operational sequences are evaluated and optimised with respect to desired product features. Having optimised the operation, a prototype of the part can be created at the facility. During prototyping, process parameters are monitored in real-time. A Case Study is presented, where a 3-axis milling operation is defined, optimised and executed using the facility.

An Architecture for Shared Management of Explicit Knowledge Applied to Product Development Processes

H. Rozenfeld / W. Eversheim (1)

STC O, 51/1/2002, P.413

Keywords: Product development, Knowledge management, Architecture

Abstract : Knowledge management is one of the main challenges in product development processes. This paper proposes an architecture based on which solutions can be implemented in order to share explicit knowledge among partners. The design of the architecture is object-oriented and comprises knowledge insertion and synthesizing methods, knowledge ontology, PD process taxonomy and process modeling methods. The paper also discusses an application of the architecture in the development of a community of interest. The first members are research institutions sharing product development-related knowledge. Industrial partners are expected to become members of the community in the near future.

Statistical and Deterministic Tolerance Analysis and Synthesis Using a Unified Jacobian-Torsor Model

L. Laperriere (2), W. Ghie, A. Desrochers

STC O, 51/1/2002, P.417

Keywords: Tolerancing, Mathematical, Modeling

Abstract : This paper presents a model for computer-aided tolerancing which enables to perform tolerance analysis and tolerance synthesis in both deterministic or statistical situations. The model combines the benefits of the Jacobian and torsor approaches developed for computer aided tolerancing. The proposed unified model is formulated using interval-based arithmetic. The paper describes how different solving engines of the same set of interval-based equations lead to different types of problems being solved, i.e. deterministic (worst case) or statistical problems. The paper also shows how the unified analysis model can be numerically inverted for performing synthesis calculations.

Approximate Product Life Cycle Costing Method for the Conceptual Product Design

J.-H. Park, K.-K. Seo, D. Wallace, K.-I. Lee (1)

STC O, 51/1/2002, P.421

Keywords: Life Cycle, Cost, Artificial Neural Network (ANN)

Abstract : Although the product life cycle cost (LCC) is mainly committed by early design stages, designers do not consider the costs caused in subsequent phases of life cycle. The estimating method for the product life cycle cost in early design processes has been required because of both the lack of detailed information and time for a detailed LCC for a various range of design concepts. This paper suggests an approximate LCC method that allows the designer to make comparative LCC estimation between the different product concepts. The product attributes at the conceptual design phase and LCC factors are introduced and the significant product attributes are determined by statistical analysis. Neural network algorithms are applied to estimate LCC by considering the identified product attributes as inputs and the LCC as output. Trained learning algorithms for the known characteristics of existing products will quickly give the estimation of LCC for new product concepts. The estimation for maintenance and energy costs of electronic appliances is shown as an example. The proposed method provides the good estimation for the LCC and gives the guidelines leading to cost-effective design decision-making at the early design stage.

Constraint-based process planning in sheet metal bending

A. Markus (2), J. Vancza, A. Kovacs

STC O, 51/1/2002, P.425

Keywords: Process planning, Constraints, Bending

Abstract : The majority of research dealing with computer-aided process planning of sheet metal bending approaches this problem as heuristic search. Since relevant engineering knowledge mostly consists of declarations that prohibit collisions and just a handful of generative rules, there are no useful means to drive these heuristics. In order to find a new way, we have made experiments with a constraint-based approach: using predefined constraint types and geometric constraint satisfaction, complex bending problems have been solved. By returning not just a single solution but a Pareto-optimal set of solutions (i.e., operation sequences, with appropriate part orientations and tools assigned) we have left the engineers freedom to apply further, not yet modeled parts of their domain knowledge.

Optimization of Cutting Conditions using Enhanced Z Map Model

M. Kang (2), S.-K. Lee, S.-L. Ko

STC O, 51/1/2002, P.429

Keywords: Computer Aided Manufacturing, Cutting Condition Optimization, Z Map Model

Abstract : The Z map has been widely used to simulate cutting operation because of its simplicity, fast computation time and robustness compared to a solid model. This paper presents an improved optimization system based on exact simulation of cutter immersion volume using the enhanced Z map model. By adopting the basic idea of anti-aliasing theory of computer graphics, the accuracy and robustness of geometric Boolean operation using Z map model can be significantly improved at approximately equal computation time. The proposed algorithm can instantaneously calculate cutting force using force buffer algorithm, and optimize cutting operation subject to several constraints on cutting condition.

STC P

Accurate Tool Height Control by Bearing Gap Adjustment

A.M. van der Wielen, P.H.J. Schellekens (1), F.T.M. Jaartsveld

STC P, 51/1/2002, P.351

Keywords: Tool positioning, Fluid bearing, Bearing gap control

Abstract : Face turning of optical surfaces on precision lathes needs high precision tool height adjustment, which may be a difficult and time-consuming task. In this paper we present a new tool adjustment mechanism based on varying the bearing gap height of the hydrostatic bearings present in precision lathe slides. Slide height variation is realised by influencing the flow to the bearing chambers. This is obtained by adding adjustable restrictions into the oil supply tubes. The bearing stiffness change is limited and stays high in comparison with other machine elements. The realised system has a fine adjustment range of 20 µm, a resolution better than 0.1 µm and a repeatability error lower than 0.1 µm.

Approaches to the Calibration of Freeform Artefacts on Coordinate Measuring Machines

E. Savio, H.N. Hansen, L. De Chiffre (1)

STC P, 51/1/2002, P.433

Keywords: Coordinate measuring machine (CMM), Uncertainty, Freeform inspection

Abstract : The paper compares two different experimental methods to establish the traceability of freeform measurements on coordinate measuring machines: i) uncertainty assessment using Modular Freeform Gauges, and ii) uncertainty assessment using Uncalibrated Objects. The first approach is an application to freeform geometries of the method described in ISO TS 15530-3 based on comparisons. The second approach is inspired by the procedure currently being developed within ISO TC213, involving repeated measurements of a given object in different orientations with variation of measuring parameters etc. The feasibility of the two approaches for freeform geometries is demonstrated through the calibration of a turbine blade.

Towards the Intelligent CMM

G.X. Zhang (1), S.G. Liu, X.H. Ma, J.L. Wang, Y.Q. Wu, Z. Li

STC P, 51/1/2002, P.437

Keywords: Measurement, Coordinate measuring machine (CMM), Intelligent technique

Abstract : ?Intelligent? CMMs are likely to become the next generation of CMMs. In this paper the main features of an intelligent CMM are proposed. In operation, the geometric and measuring information of the part would be extracted from its CAD file. A measuring program including the selection of probe and accessories, determination of the features and parameters to be measured, number and positions of the measured points would then be generated automatically. The position and orientation of the part would be recognized by a CCD camera mounted on the CMM. Based on all this information an optimal measuring path is generated and possible collisions are taken into account. The feasibility and reliability of the system are evaluated by measuring several real workpieces.

Quality of 3D digitised points obtained with non-contact optical sensors

A. Contri, p. Bourdet (1), C. Lartigue

STC P, 51/1/2002, P.443

Keywords: 3D digitising, Uncertainty, Calibration

Abstract : Today digitising systems deliver large sets of data points which are representative of an object surface, in a relatively short time. These digitised data are generally exploited by applications such as reverse engineering, inspection or free form copying. However, the quality of the point exploitation is widely linked to the point quality, i.e. to the quality of the digitising process. To answer a part of this problem, we propose a method to locally evaluate the uncertainty of location of a 3D point in the whole measuring space. This uncertainty integrates errors due to digitising noise and optical phenomena. In particular, the use of noisy data in the calibration method implies a dispersion on the resulting 3D point as obtained from its 2D CCD location.

Precision Measurement of Multi-Degree-of-Freedom Spindle Errors Using Two-dimensional Slope Sensors

W. Gao, S. Kiyono, E. Satoh / T. Sata (1)

STC P, 51/1/2002, P.447

Keywords: Metrology, Spindle, Sensor

Abstract : A measuring system consisting of three two-dimensional surface slope sensors is developed for spindle error and roundness measurement. The sensors, which are in the same XY-plane perpendicular to the spindle axis (Z), are placed around a cylindrical workpiece mounted in the spindle. The workpiece out-ofroundness and the X- and Y-directional components of the spindle radial error motion can be separated from each other using the radial direction outputs of sensors. On the other hand, the two-directional components of the spindle angular error motion can be obtained accurately from the angular direction outputs of sensors. Experiments of spindle error and roundness measurement were carried out.

Displacement Uncertainty in Interferometric Radius Measurements

T.L. Schmitz, C.J. Evans (1), A. Davies, W.T. Estler (2)

STC P, 51/1/2002, P.451

Keywords: Radius measurement, Interferometry, Uncertainty

Abstract : Interferometric radius measurements may be completed using a radius bench, where radius is defined as the displacement between the confocal and cat?s eye nulls (identified using a figure measuring interferometer). Measurements of a Zerodur sphere have been completed on the X-ray Optics Calibration interferometer (XCALIBIR) and a coordinate measuring machine. Larger recorded disagreements than indicated by the current uncertainty analysis call for an exploration of the analysis model. This paper details uncertainties associated with the use of multiple displacement measuring interferometers (DMIs) to record motion in a single axis by treating the specific case of displacement measurement on XCALIBIR using three DMIs equally spaced around the optical axis.

The Virtual Interferometer - A Tool for the Systematic Assessment of Error-Sources in Interferometry

T. Pfeifer (2), A. Bai

STC P, 51/1/2002, P.455

Keywords: Interferometry, Simulation, Measurement uncertainty

Abstract : The knowledge of measurement uncertainties is essential for the proper assessment of product-quality, for controlling production processes and to ensure comparability with other types of metrological instruments. However, the assessment of measurement uncertainties becomes more complicated when high-precision metrology is considered. In this paper a procedure for the assessment of the measurement uncertainty of interferometers with the help of a virtual instrument, the so-called ?Virtual Interferometer?, will be presented. In conjunction with finite element analysis the Virtual Interferometer allows to determine the influence of error-sources that cannot be modelled with commercial ray tracing software, like e.g. the thermal expansion of optical components.

Measurement Uncertainty and Machine Tool Testing

W. Knapp (2)

STC P, 51/1/2002, P.459

Keywords: Machine tool, Test uncertainty, Tolerance

Abstract : According to international standards measurement uncertainties have to be stated with all measurements, including results from machine tool testing. For average industrial conditions measurement uncertainties are estimated for positioning measurements with laser interferometers and linear scales, for straightness measurements with laser interferometer and straightedge, and for pitch measurements. The results, i.e. the test uncertainties, are discussed and compared with average tolerances given in ISO standards for the corresponding test procedures. Uncertainties are not estimated for optimum conditions in order to make more people aware, that the alignment of the measurement device, temperature effects and repeatability of the machine tool and the measurement device might cause larger uncertainties than the uncertainty of the device alone.

Statistical Approach to Assessments of Geometrical Accuracy

V.T. Portman (2), Y.L. Rubenchik, V.G. Shuster

STC P, 51/1/2002, P.463

Keywords: Form accuracy, Uncertainty, Roundness

Abstract : Statistical properties of the minimax assessments of the geometric accuracy are investigated. The cases when a distribution of the point deviations differs from the normal distribution are especially considered. Among such cases, the roundness deviations of the profile, which is composed of few harmonics, is of fundamental importance. A set of the point positions within the minimum zone (MinZ) is considered as a random sampling, and the width of the MinZ presents the sampling range. Range distributions vs. the number of the harmonics, amplitude ratios, and the number of points of measurements are considered. Information about the power spectrum of the measured profile is applied for numerical estimations of the uncertainty through the use of these distributions; this information yields a large dividend in accuracy of the uncertainty assessments. An application example is simulated.

Uncertainty Analysis of the New Spanish National Pressure Standard

A. Herrero, Mª.C. Matilla, N. Cereceda, S. Ruiz, R. Bueno (1)

STC P, 51/1/2002, P.467

Keywords: Ultraprecision Engineering, Measuring Instrument, Error Budgeting

Abstract : This paper presents the project for developing a new interferometer-based mano-barometer. This system will constitute the National Primary Pressure Standard maintained at CEM. This device is based on the ancient Torricelli?s experience and applies modern techniques in order to obtain a very accurate instrument. This system will allow the calibration up to 300 kPa with uncertainties about 5·10-6. Laser interferometry is applied and special attention is given to the accurate determination of fluid density. Hence, this paper describes the technology used in the project. Its influence on the measurement is being studied prior to the manufacturing and assembling phases.

STC S

Nano-Texturing of Surfaces by Constricting Epitaxial Growth of Molecules

A. Kakuta, N. Moronuki, Y. Furukawa(1)

STC S, 51/1/2002, P.323

Keywords: Nano-texture, Physical vapor deposition (PVD), Single crystal silicon

Abstract : This paper discusses an application of molecular beam epitaxy (MBE) to a nano-texturing process. Silicon molecules grow laterally along the specific crystal planes of a silicon substrate under a specific condition. It was found that a pre-processed array of holes could compose nano-texture because it constricted these lateral growths to the specific directions of substrate. This paper clarifies the mechanism and the design of texturing. Depending on the arrangement of the hole array, various textures were obtained and their geometry and accuracy were also discussed.

Calibration and Industrial Application of Instrument for Surface Mapping based on AFM

H.N.Hansen, N. Kofod, L. De Chiffre (1), T. Wanheim (1)

STC S, 51/1/2002, P.471

Keywords: Surface topography, Atomic force microscopy (AFM), Coordinate measuring machine (CMM)

Abstract : The paper describes the calibration and application of an integrated system for topographic characterisation of fine surfaces on large workpieces. The system, consisting of an atomic force microscope mounted on a coordinate measuring machine, was especially designed for surface mapping, i.e., measurement and tiling of adjacent areas. A calibration procedure was proposed involving a glass artefact featuring chromium lines with different pitch distances, giving the possibility to identify the exact position of single surface areas. The calibrated system was used to surface map a hip joint prosthesis consisting of a steel sphere with a polished surface having 3 nm roughness.

Silicon Standards for Assessment and Calibration of Stylus Probes

J. Frühauf, H. Trumpold (1)

STC S, 51/1/2002, P.475

Keywords: Surface measurement, Stylus probe, Silicon calibration tool

Abstract : When using tactile instruments the representation of the extracted surface profile is influenced by the properties and the state of the stylus probe. It will be shown that monocrystalline silicon is an excellent material for standards and tools to assess the stylus probe properties. Very precise structures can be realised by etching. A set of silicon standards will be presented. Furthermore, the results of investigations concerning the detection of the shape of the stylus tip, the measurement of the stylus force and the correction of profiles which are distorted by the circular movement of the stylus arm will be discussed.

Roughness Measurement by Analysing Slightly Defocused Images Obtained by Acoustical Microscopy

M. Steinbach, G. Goch (2), U. Laun

STC S, 51/1/2002, P.479

Keywords: Roughness measurement, Acoustical microscope, Surface quality

Abstract : Acoustical microscopes are standard instruments for investigating and characterizing technical surfaces, but until now they are not convenient for a quantitative roughness inspection. Analysing a few slightly defocused acoustical images by some adapted image processing opens a new, fast and easy to use possibility to measure the integral surface roughness with high accuracy.

Investigation of Polished Single Crystal ZnO by Nanoindentation

D.A. Lucca(1), M.J. Klopfstein, R. Ghisleni, G. Cantwell

STC S, 51/1/2002, P.483

Keywords: Surface, Polishing, Nano-indenting

Abstract : The near surface mechanical response of polished single crystal ZnO has been investigated by nanoindentation. Surfaces of (0001) ZnO crystals were prepared by mechanical polishing with 1/4 µm and 1 µm diamond abrasives and by chemomechanical polishing. Values for the critical load at the onset of yielding, the elastic modulus and the depth dependent values of hardness were measured. Results were compared to etched (0001) surfaces and (0001bar), {101bar0} and {112bar0} surfaces which had been chemomechanically polished. Surface preparation and crystal orientation were both found to have an effect on the near surface mechanical response.

Importance of Micro/Macro Interaction in the Mechanism of Brittle Mode Cutting

T. Inamura (2), N. Takezawa, S. Shimada (2)

STC S, 51/1/2002, P.487

Keywords: Machining, Brittle material, Computer simulation

Abstract : The mechanism of brittle mode cutting has been investigated from the viewpoint of the micro/macro interaction. The concept of micro/macro interaction is first described briefly, and the method to incorporate the concept into the Variable Resolution Molecular Dynamics (VRMD) has been discussed, together with the explanation of the VRMD itself. The results of the VRMD without, with incomplete and with complete micro/macro interaction have been compared and the crucial role of the interaction has been clarified.

Improvement of Corrosion Resistance in Metallic Biomaterials using a New Electrical Grinding Technique

H. Ohmori (2), K. Katahira, J. Nagata, M. Mizutani, J. Komotori

STC S, 51/1/2002, P.491

Keywords: Electrical Grinding, High Quality Surface, Corrosion Resistance

Abstract : A new electrical grinding method for the fabrication of machined surfaces with desirable characteristics for biomaterials and other engineering applications is presented. Conventional biomaterials, such as stainless steel and titanium alloy, require enhanced chemical stability and wear resistance, which are dependent on the quality of the surface oxide layer. However, it is difficult to produce sufficiently homogenous oxide layers by alumina polish finishing alone. The electrical grinding method proposed in this study, in which electric current is applied to the grinding fluid in the machining process, improves oxide formation on the finished surfaces, thereby realizing finished surfaces with extremely thick and stable oxide layers. Compared with alumina polishing, electrical grinding yields machined surfaces having excellent corrosion resistance.

Design of Surface Micro-structures for Friction Control in Micro-systems Applications

D.E. Kim, K.H. Cha, I.H. Sung / J. Bryan (1)

STC S, 51/1/2002, P.495

Keywords: Friction, Wear, Micro-structured surface

Abstract : In this work, the effectiveness of controlling the frictional force at the micro-scale using well structured surface micro-grooves is demonstrated. Such micro-structured surfaces are designed to eliminate wear particles or contaminants from the sliding interface, thereby, minimizing the effect of surface plowing. Also, the surfaces are designed to minimize the effective area of contact, which is found to have a profound effect on the magnitude of the surface force for micro-systems. Experimental evidence of stiction/friction reduction even at high relative humidity by using such micro-structured surfaces are provided in this work. The results of this work can be utilized in optimization of tribological surface design for micro-systems applications.

Fast Inspection of Larger Sized Curved Surfaces by Stripe Projection

B. Denkena, H. Ahlers, F. Berg, T. Wolf / H.K. Tönshoff (1)

STC S, 51/1/2002, P.499

Keywords: Optical inspection, Stripe pattern, Form errors

Abstract : Sheet metal is often used for components which, for functional reasons or visual effects, have to meet high requirements concerning form accuracy as well as smooth surface curvature, while dimensional errors are of minor significance. In this paper a measuring system which allows automatic detection of waviness and form errors is presented. The system is based on a stripe projection method using a high resolution line scan camera. Particular focus is put on achieving both short measuring times and high resolution in depth, aiming at reliable automatic recognition of dents and waviness of only 10 µm depth within less than 10 seconds per m².

Evaluation of Honed Cylinder Bores

F. Puente Leon / G. Spur (1)

STC S, 51/1/2002, P.503

Keywords: Honing, Surface texture, Automated visual inspection

Abstract : The quality of the honing texture on cylinder bores of combustion engines plays an important role with respect to oil consumption, noxious emissions, and running performance. To evaluate honed surfaces objectively, features describing the surface texture are extracted from 2-D data of the surface. The paper focuses on two crucial stages of the data analysis: the preprocessing, which aims at suppressing irrelevant components and enhancing the information of interest, and the feature extraction, which yields reliable numerical estimates of the surface characteristics of interest, like the honing angle, groove parameters, surface defects etc. The assessment results can easily be adapted to user-specific ratings.

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