Unified failure analysis for tubular hydroforming

A numerical and experimental study of failure development for tubular hydroforming under combined axial force and internal pressure are presented in this paper. In this forming process, two distinct failure modes occur, the necking or bursting and the wrinkling or buckling. The originality of the study presented is that these two phenomena are considered in an unified approach based on the rate of internal and external powers. The governing equations for the onset of both failure modes are established. Two local criteria are derived in the context of explicit codes and compared to experimental results obtained from the hydroforming of a stainless tube.