On the Axisymmetric Crushing of Circular Tubes

By using general rigid-perfect plasticity theory, the problem of plastic deformation of circular tubes subjected to axial compressive loads is reexamined in this paper. After a detailed analysis of axisymmetric deformation process of circular tubes, a more realistic model is proposed, which takes into account the extensibility of the shell in both axial and circumferential directions, and also the internal flexion of the wall. The main purpose of this study is to clarify certain assumptions commonly used in crushing mechanics, such as axial inextensibility, non-variation of the wall thickness in continuously deformed zones and the minimum principle.