Cae-based Sheet Metal Blank Inverse Technology And Applications

The determination of the optimum blank is one of the key and difficult problems in sheet metal forming. Reasonable design of the blank will decrease the possibility of wrinkle and fracture, and increase the formability obviously.A Mesh Mapping Method based on the FEM results has been proposed to predict the optimum blank in sheet metal forming in this thesis. The method assumed that the adaptive technique was not been used during the finite element simulation. The basic idea of the presented method is to map the target contour to the blank wire at final configuration after the punch was released completely and the optimal blank can be obtained according to the blank wire at the initial configuration. After the iteration loops subjected to the shape error constant, the size and shape of the blank can be determinated very accurately as long as the FEM results were accurate enough. Several examples are applied to confirm the validity, effectivity and versatility of the presented method.It is possible for the presented method to consider the problems about the technique allowance, for example, for drawbed, aided plane and crimp. Not only the rough profile but also the exact optimum blank can be obtained by controlling of the shape error constant. Especially, the presented method can deal with the parts with the holes. Due to specifying the exact optimum blank, some subsequent techniques will be taken out and the production cost will been decreased.The blank prediction system of U-shape has been developed using the Radial Basis Function Network to get the optimal blank rapidly for practical purpose. The Orthogonal table mixing with the Uniform table was proposed to specify the specimens for neural network, which improved the precision of prediction and decreased the test numbers.The big 'fool' prediction system has been introduced and some viable methods have been given. The system will include the prediction of the blank shape, and some other design parameters in automotive sheet metal forming.