The Elastic-Plastic Response of Thin-Walled Tubes Under Combined Axial and Torsional Loads: Part I—Monotonic Loading

Abstract

This paper investigates the elastic-plastic response of thin-walled tubes subjected to combined axial and torsional loads. The kinematic hardening model is used and exact closed-form solutions are obtained for linear loading paths. The characteristics of the stress-strain relationships are discussed and the corresponding movements of the yield center are illustrated. The response of the material under nonproportional loading is proved to be path-dependent, and the hardening behavior is shown to be different from that under proportional loading. The investigation then shows that such a difference will finally disappear when the stresses tend to infinity.