Abstract:On the basis of the rigid viscoplastic FEM theories, a surface defect prediction for plastic forming process by FEM numerical simulation has been deeply studied. Some technical treatments and algorithms of defect prediction are proposed. Using this method, the processes of defect initiation and development during CONFORM process are predicted successfully, and some critical technological parameters are obtained. Therefore, it is also an extension for application fields of rigid viscoplastic FEM to predict forming defect.

Key words: continuous extrusion forming surface defect prediction method rigid viscoplastic FEM