Based on the Curson-Tvergaard void damage plastic potential equation and by using orthogonal rules of plastic material, the influence of void volume fraction on stress and strain fields was introduced into Levy2Mises flow rules. The variation principle of rigid plastic material with void degradation was demonstrated. Furthermore, FEM equations coupled with damage factor were presented to study the void growth and the criterion to judge the damage was also given. Using the developed system, the fine blanking process was simulated and the sheared surface of the part edge was predicted. Meanwhile, the influence of process parameters, such as punch-die clearance, V-ring force, counter force, radius of punch and die edges, on the height and quality of the sheared surface was analyzed. The calculation results were compared with the experiments, which can be used to guide the design of fine2blanking process.

In order to continuously analyze the whole fine-blanking process, from the beginning of the ooperation up to the total rupture of the sheet-meta, without computational divergenec, a 3-Drigid visro-plastic element method based on Gurson void model was developed. The void volume fraction wasintrodced into the fineite elment anethod to document to the virtual work theory in which both the sheet was prodicted and the crack propagation was geometrically fulfilled in the simulation by separating the nodes according the stress state. Furthermore the influences of different state-variables on the defomation process were also studied.

On the basis of the practical situation of cold forging process planning, the disadvantages of a rule-based solution are discussed, and a case-based reasoning-based cold forging process planning (CFPP) system model is proposed. Several key problems involved are analyzed, among which a feature-based part representation scheme and a two-level retrieval mechanism are introduced to solve the problems of case representation and case retrieval. It is established in this paper that case-based reasoning-based CFPP is a promising technology for both long-term research and the promotion of efficiency for current cold process planning systems. 2001 Elsevier Science B.V. All rights reserved.

This paper introduces the application of a second generation expert system in blankinng technology. Depending on the empiiical knowledge of domain experts and field literature, an expert system can play an important role in the field of blanking technology. An object oriented blackboard modal is given which can realize hyhiid knowledge representation, such as prodnction roles, frameworks and procednres. This paper mainly discusses the structure of the blackbom-d model mid hybrid knowledge representation in blabking technology expert system. Since strip layout is a crucial and deteimining part in blanking technology, given here is an exmnple of a blackboard modal supporting hybrid knowledge representation about the strip layont process.