On relating redistributed elastic and inelastic stress fields

摘要

The classical lower bound theorem in plasticity states that the load required to create equilibrium stresses in a structure that are below yield will always be less than or equal to the collapse load. Recent advances in determination of lower bound limit loads involve repeating elastic analyses after systematic modification of elastic moduli. The intention is to obtain lower bound limit loads from stress fields that would progressively approach a state similar to one at plastic limit. The gradual transformation of statically admissible stress fields from elastic to limit state can be compared to those corresponding to power-law creep indices, ranging from one to infinity. This paper attempts to investigate the possibility of establishing such relationships on a one-to-one basis, by considering standard component configurations.