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.

The anisotropy of stamped sheet metal exerts evident effects on the formability. Barlat aix-component yield function was introduced into theelastoplastic finite element formulation based on the principle of virtual velocity and the discrete Kirehhoff triangular element model. The flanging earing in cylindrical capdrawing process of circular sheet metal was aumerically simulatad. Th influence of anisotropy on the forming process was studied.

The finite element method (FEM) and the finite volume method (FVM) nurmeircal sinrmalation methods have been widely used in forging industries to imrovethe quality of products and reduce the costs. Because of very concentrative largedeformation during the aluminum extrusion processes, it is very difficult to simulate the whole forming process only by using either FEM or FVM. In order to solve this problem, an FEM and FVM compoun simulation method was proposed. The theoretical equation of the compound sinmulation method were given and the key techniques were studied Then, the cofiguration of the compound simulation system was estabished. The tube extrusion process was simulated successfully so as to prove the validity of this approach for aluminum extusion processes.

Springback of sheet metal induced by elastic recovery is one of major defects in sheet metal forming processed. Springback is influenced by many factors including properties of the sheet material and processing conditions. In this paper, springback simulation is conducted and comparisons between results based on different processing variables are illustrated. Furthermore, the discovery of knowledge of the effects of geometry and process parameters on springback from FEM results becomes increasingly important, as the number of numerical simulation has grown exponentially. Data mining is an effective tool to realize knowledge discovery in simulation results. In the present paper, a data-mining algorithm, rough sets theory (RST), is applied to analyze the effects of process parameters on springback in U-bending.