CIRP Annals Online sorted by Year and Volume




Computer Aided Disassembly Planning: State of the Art and Perspectives
M. Santochi (1), G. Dini (2), F. Failli  
STC A,  51/2/2002,  P.507
Keywords: Disassembly, recycling, planning
Abstract : In the last two decades, the problems related to the preservation of the environment and the resources of the planet have been dramatically highlighted by different phenomena (thinning of ozone layer, greenhouse effect, decreasing of forests, air pollution, increasing difficulties in the industrial and domestic waste management, etc.). In order to face this situation, the governments have begun to apply rules to control some aspects of the industrial production and energy. Consequently, the environment has become an interesting issue also for the researchers. A key-point in these new techniques, grouped under the name of ?sustainable development?, is the disassembly and recycling of the end-of-life goods, necessary to minimize the environmental impact of discarded materials and energy consumption. In this keynote paper the state of the art of the software tools developed to help the designer and the dismantler in the optimization of the disassembly-for-recycling of discarded goods is discussed. The architecture of a complete and general computer aided disassembly planning system is described and a number of system developed both in the academic institutes and in the industry are shown together a review and classification of the different adopted solutions.


Machining of Composite Materials
R. Teti (2)  
STC C,  51/2/2002,  P.611
Keywords: Machining, Composite Materials, Conventional Cutting Processes
Abstract : Machining of composite materials is difficult to carry out due to the anisotropic and non-homogeneous structure of composites and to the high abrasiveness of their reinforcing constituents. This typically results in damage being introduced into the workpiece and in very rapid wear development in the cutting tool. Conventional machining processes such as turning, drilling or milling can be applied to composite materials, provided proper tool design and operating conditions are adopted. An overview of the various issues involved in the conventional machining of the main types of composite materials is presented in this paper.

 STC Dn 

New Trends in Rapid Product Development
A. Bernard (2), A. Fischer (2)  
STC Dn,  51/2/2002,  P.635
Keywords: Rapid product development, technology modeling, data integration
Abstract : This keynote paper presents an overview of new approaches in rapid product development from the design point of view. The evolution of the market has necessitated the reduction of time-to-market, mainly because the product life cycle is shorter, but also because it is very important to proceed more rapidly from an initial conception to a mass production object. As a result of newly evolved software environments, knowledgebased systems, and product data management, processes for integrated design and manufacturing for new products have emerged. Due to this evolution of rapid prototyping technologies, it has become possible today to obtain parts representative of mass production within a very short time. This keynote paper provides an overview of the actual trends in all the components that affect the speed and efficiency of product development, in particular all the possibilities available to the designer, from the earliest stages of a product's life cycle.


Laser Machining by short and ultrashort pulses, state of the art and new opportunities in the age of the photons
Meijer (1), K. Du, A. Gillner, D. Hoffmann, V.S. Kovalenko (2), T. Masuzawa (1), A. Ostendorf, R. Poprawe, W. Schulz  
STC E,  51/2/2002,  P.531
Keywords: Micro-machining, Laser, Ablation
Abstract : An overview is given of the applications of short and ultrashort lasers in material processing. Shorter pulses reduce heat-affected damage of the material and opens new ways for nanometer accuracy. Even forty years after the development of the laser there is a lot of effort in developing new and better performing lasers. The driving force is higher accuracy at reasonable cost, which is realised by compact systems delivering short laser pulses of high beam quality. Another trend is the shift towards shorter wavelengths, which are better absorbed by the material and which allows smaller feature sizes to be produced. Examples of new products, which became possible by this technique, are given. The trends in miniaturization as predicted by Moore and Taniguchi are expected to continue over the next decade too thanks to short and ultrashort laser machining techniques. After the age of steam and the age of electricity we have entered the age of photons now.


Mushy / Semi-Solid Metal Forming Technology ? Present and Future
M. Kiuchi (1), R. Kopp (1)  
STC F,  51/2/2002,  P.653
Keywords: Semi-Solid, Forming, Modelling, Rheology
Abstract : Mushy, semi-solid and / or thixo processing of metals (alloys) is becoming popular as a new potential manufacturing technology for parts and components in automobile, electronic and machine industries. Internal structures and mechanical properties of those metals that include solid and liquid fractions are quite different from those of hot or molten metals. Diversified possibilities are known today to process those metals based on die casting, hot metal forming or polymer injection technologies, each of which has its own specific advantages and disadvantages. Up to now thixocasting and thixomolding have been used in industrial applications for light metal alloys. The potentials of those processes are wider by far however. They include the processing of specially designed alloys and composites, the combination of forming and joining processes as well as reduction of production costs and energy consumption.


Process Monitoring in Grinding
H.K. Toenshoff, T. Friemuth, J.C. Becker  
STC G,  51/2/2002,  P.551
Keywords: Grinding, sensor, process monitoring
Abstract : The grinding process is characterised by a high number of cutting edges undergoing non-uniform wear, this also typifies a highly non-stationary process. Pure process modelling in order to understand the grinding mechanisms and to predict the work result is difficult. In view of this, several approaches by academia and by industry were made to address this issue. One such approach is the development and implementation of process monitoring in grinding. The work presented in this paper summarises the various elements and approaches in process monitoring during grinding. The paper deals with the relevant quantities that describe the grinding process itself and the ensuing work result. Furthermore the different sensing techniques are introduced to measure the relevant quantities. Finally an overview is presented as to the strategies and techniques involved in the interpretation of the measured data and the subsequent control action initiated in order to close the process control loop.


Parallel Kinematic Machines Tools - Current State and Future Potentials
M. Weck (1), D. Staimer  
STC M,  51/2/2002,  P.671
Keywords: Manufacturing Equipment, Parallel Machines, Performance
Abstract : Parallel kinematics have recently attracted attention as machine tools because of their conceptual potentials in high motion dynamics and accuracy combined with high structural rigidity due to their closed kinematic loops. This paper, prepared with input from CIRP colleagues as well as of machine manufacturers and end-users involved in PKM, attempts to review the development of parallel kinematics for machine tools, their practical application and their performance compared to classical machine tools.


Production in Networks
H.-P. Wiendahl (1), S. Lutz  
STC O,  51/2/2002,  P.573
Keywords: Manufacturing, Production network, Production planning and control
Abstract : New types of cooperation between companies in the manufacturing sector are coming into being. Since nowadays the creation of and involvement in supply chains is for most companies standard practice, new forms of cooperation are now emerging: production networks. The paper describes current developments in the field of production networks along with techniques and methods for their operation and management.


Large-Scale Metrology ? An Update
W.T. Estler (2), K.L. Edmundson , G.N. Peggs (1), D.H. Parker  
STC P,  51/2/2002,  P.587
Keywords: Dimensional metrology, Distance measurement, Measurement uncertainty
Abstract : Developments in large-scale engineering metrology since the 1978 report of Puttock are reviewed. Advances in optical technology and fast, low-cost computation have led to wide-spread use of laser trackers and digital photogrammetry for general-purpose coordinate metrology. Techniques for highaccuracy straightness measurement, precision leveling, and absolute distance metrology are described, together with approaches to compensation for the effects of atmospheric refraction. Methods for uncertainty evaluation are discussed and several illustrative examples are presented.
Optical Methods for Dimensional Metrology in Production Engineering
H. Schwenke, U. Neuschaefer-Rube, T. Pfeifer (2), H. Kunzmann (1)  
STC P,  51/2/2002,  P.685
Keywords: Dimensional Metrology, Optical Methods, Production Engineering
Abstract : Metrology in production engineering must be fast, accurate, robust and automated, and ideally integrated into the production line. In many respects, optical methods seem to fulfil these requirements. Although optical methods have a long tradition in dimensional metrology, the rapid progress in the development of optoelectronic components and availability of increased computational power makes many new technical approaches possible. This paper provides a technical overview of the optical methods available for dimensional metrology. Methods for the measurement of length, angle, surface form and spatial co-ordinates are described. The paper summarises both the metrological characteristics and the technical limitations of the methods. Furthermore, it presents some new and promising approaches that, in the future, may play an important role in dimensional metrology for production.


Emerging Trends in Surface Metrology
P.M. Lonardo(1), D.A. Lucca (1), L. De Chiffre (1)  
STC S,  51/2/2002,  P.701
Keywords: surface, metrology, surface integrity
Abstract : Recent advancements and some emerging trends in the methods and instruments used for surface and near surface characterisation are presented, considering the measurement of both topography and physical properties. In particular, surfaces that present difficulties in measurement or require new procedures are considered, with emphasis on measurements approaching the nanometre scale. Examples of new instruments and promising innovations for roughness measurement and surface integrity characterisation are presented. The new needs for tolerancing, traceability and calibration are also addressed.