基于韧性断裂准则的铝合金板材成形极限预测

为了准确地预测铝合金板材成形极限，将韧性断裂准则引入到数值模拟中。在数值模拟获得的应力应变值基础上，采用简单拉伸试验和数值模拟相结合的方法确定了韧性断裂准则中的材料常数，并应用该韧性断裂准则预测了铝合金LYl2(M)的圆筒件拉深和半球形凸模胀形的成形极限。预测结果与实验值吻合较好，该韧性断裂准则能够预测铝合金板材成形极限。

Application of ductile fracture criterion to prediction of forming limit in aluminum alloy sheet forming

To accurately predict the forming limit in aluminum alloy sheet forming, ductile fracture criterion is introduced into numerical simulation. On the basis of the values of stress and strain calculated from numerical simulations, the material constants in ductile fracture criterion were determined by the combination of tension tests with numerical simulation, and the forming limits in cylindrical deep drawing and hemispheric punch bulging of aluminum alloy sheet LY12(M) were predicted. The experiments verify that the predicted results are in agreement with the experimental ones, and that the ductile fracture cristerion can predict the forming limit of aluminum alloy sheet.