Blank layout is one of the most imporant processes in stamping die design. As the major cost in sheet metal stamping is te material cost, any efforts to minimise the scrap may result in substantial savings not only in strip material, but also in overall production. This paper is maily trageted at establishing a practical blank layou optimisation system forstamping die by using AutoCAD's ObjiectARX toolkit. The basic principles of blank layout optimistaion are first descrbed. Not only a suitable algorithm for layout calculation, but also the manufacturing requirements an user operation are fully considered in this system. Finally, an algorithm for blank shape offsetting is proposed to solve the problem of selfintersection in offset curves, andd the traditional' I-step translation' algorithm for the caluction of layout parameters is improved to eliminatte the confilic between preecsion and efficiency in the layout optimisation.

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.

A rate-inderpendent polyerystallme plasticity constitutive model considering sclf and latent hardening was develped. Next, a new orientation probabillity assignment method was proposed and the crystal orientations were assigned to FE integration points, which reprcenet crystals and can rotate individually. Then eup drwing of FCC aluninum sheet was studied usig erystalline plasticity finite fimite element analysis. The results show that the validity of proposed model is proved throuth compatison bet ween numerical results and experimental. For the roled aluminum sheetm which contains strong {001}<110> texture, caring is formed at 45