CIRP Annals Online sorted by Year and Volume




Relevance of Assembly in Global Manufacturing
K. Feldmann (1),H. Rottbauer, N. Roth (2)  
STC A,  45/2/1996,  P.545
Keywords: Assembly, Globalization, Flexible Manufacturing
Abstract : Within the framework of entire production assembly plays an exceptional and specific role. In this step of the value adding chain the different components lead to the function determining unit. The globaliza255tion of the markets as well as technological innovations increasingly cause a redesign of the arrange255ment of the value adding chain in the global manufacturing network. Concerning the site selection for assembly plants two major strategies can be distinguished: Assembly follows the market and/or is shifted into regions of low labor costs. The global division of labor is supplementarily favored because of new possibilities of telecommunications. A decentralized distribution of the assembly capacities can lead to productivity disadvantages due to the loss of economies of scale. This can in turn be compen255sated by local production alliances. State and specific problems of global networks in assembly will be analyzed in four relevant product areas.


Environmental and safety aspects of electrophysical and electro chemical processes
H.K. Toenshoff (1), R. Egger, F. Klocke (2)  
STC E,  45/2/1996,  P.553
Keywords: Environmental impact, Electrical discharge machining (EDM), Laser beam machining (LBM)
Abstract : Environmental protection ranks high in public opinion, and has become an important part of market eco255nomy. Especially industrial production is linked with risks to the environment. The following paper deals with laser beam, electrical discharge and electrochemical machining, which represent a significant area of manu255facturing technology. Despite various advantages, these processes may generate solid, liquid or gaseous by-products presenting hazards for workers or the environment. The sort and quantity of the hazardous substances, and suitable measuring methods are discussed. Furthermore, strategies to reduce emissions and to protect environment from possible impacts are explained.


Numerical process simulation for tool and process design in bulk metal forming
T. Altan (1), V. Vazquez  
STC F,  45/2/1996,  P.599
Keywords: Process Simulation, Metal Forming, Forging, Tooling
Abstract : Global competition requires that manufacturing industry utilizes practical and proven CAD, CAM and CAE techniques for rapid and cost effective process design and die manufacture. Thus, numerical simulation of bulk metal forming processes is increasingly applied to eliminate forming defects, predict and optimize process variables, and to predict stresses in dies for preventing premature die failure. This paper reviews the latest state of technology and describes several successful applications. Ongoing developments and future trends are also discussed.


Grinding Mechanisms for Ceramics
S. Malkin (1),T.W. Hwang  
STC G,  45/2/1996,  P.569
Keywords: Grinding, Ceramics
Abstract : The widespread utilization of high strength ceramic materials has been limited by the high cost of machining these materials by grinding. A technological basis for cost-effective ceramic machining requires a fundamental understanding of the prevailing grinding mechanisms. The present paper is intended to provide an overview of what happens during grinding as abrasive grains cut through ceramic workpiece materials. Most past research on grinding mechanisms for ceramics has followed either the "indentation fracture mechanics" approach or the "machining" approach. The indentation fracture mechanics approach likens abrasive workpiece interactions to idealized small255-scale indentations. The machining approach typically involves measurement of cutting forces together with microscopic observations of grinding debris and surfaces produced. Both approaches provide important insights into the grinding mechanisms for ceramic materials.


Flexibility and its Measurement
G. Chryssolouris  
STC O,  45/2/1996,  P.581
Keywords: Flexibility, Measurement, Manufacturing
Abstract : Flexibility is a major factor for increasing the competitiveness of a manufacturing system. Flexibility, however, can not be adequately considered in the decision making process, if it is not properly defined in quantitative terms. In this paper different types of flexibility are presented and quantitative definitions of flexibility are discussed. In the context of this analysis, flexibility is defined as the sensitivity of the manufacturing system to change. The paper discusses also a quantitative definition of flexibility derived from the analogy of manufacturing and mechanical systems. The discussion includes industrial applications.


Self-Calibration: reversal, redundancy, error separation and "absolute testing"
C.J. Evans (2), R.J. Hocken (1), W.T. Estler  
STC P,  45/2/1996,  P.617
Keywords: dimensional metrology, kinematic error correction, quality assurance
Abstract : Over the years many techniques have been developed for accurate measurement of part features without reference to an externally calibrated artefact. This paper presents a partial survey of such methods for dimensional metrology, their ranges of application, and their limits. Finally, the paper attempts to distil the common features of the various methods in the hope that this may provide the basis, or inspiration, for development of "new" methods.


Progress in 3D Surface Micro255topography Characterisation
P.M. Lonardo (1), H. Trumphold (1), L. De Chiffre (2)  
STC S,  45/2/1996,  P.589
Keywords: Surface topography, measurement, parameters
Abstract : The recent advancements achieved in 3D analysis of surface micro-topography have raised a great interest of researchers and industrial users for the possibilities of the new techniques, in spite of their major complexity. In this paper the state-of-the-art in measurement methods, reference surfaces, visualization techniques, definition and use of parameters is reviewed, considering advantages and limits of the 3D characterization. The need to develop further studies on the functional meaning of parameters is highlighted. Finally, comments on traceability and standardization are given.