Work Bounds and Associated Deformation of Cyclically Loaded Creeping Structures

Abstract

In this paper the deformations of a beam subject to cyclic bending moment and a thick-walled cylinder subject to cyclic internal pressure are investigated for an elastic/time hardening/perfectly plastic material. Bounds [1, 2] are computed on the work done by the applied loads over a cycle when the material has reached a cyclic state of stress. The bounds provide the extreme states when the cycle time is either large or small compared with a characteristic time of the material. It is found that the difference between the bounds is generally very small. This result is discussed in relation to recent work by Williams and Leckie [3].