Numerical prediction of bursting failure in tube hydroforming by the FEM considering plastic anisotropy

摘要

Bursting in tube hydroforming is an irrecoverable phenomenon due to local instability under excessive tensile stresses. In this paper, finite element analyses for the bursting failure prediction in tube hydroforming under combined internal pressure and independent axial feeding are carried out. The diffuse plastic instability of a tube is employed to numerically predict the hydroforming limit. For anisotropic tubes the incremental theory based on the Hill's quadratic plastic potential is also adopted. Through the above theory, influences of the plastic anisotropy on the limit strain and the bursting pressure are investigated. Finally, it is concluded that the proposed approach would be able to predict the bursting failure numerically, therefore that can be extended to a wide range of practical tube hydroforming processes.