Direct computation of asymptotic states for ratcheting prevention in elastoplasticity

Abstract

This thesis summarizes three contributions to improve design accounting elastoplasticity under cyclic loads. (i) The development of a direct method to compute the asymptotic steady-state solution in ideal elastoplasticity. Validation examples show that the method is fast and accurate. The performance ranges from one to two orders of magnitude higher than incremental analysis. (ii) The performance allowed the development of a direct strategy to identify the structural ratchet-limit. The procedure applies to periodical loads and has no limitations on the number of applied loads. (iii) The upgrade of the asymptotic solution method with nonlinear kinematic hardening, which is required to model the Baushinger effect and material ratcheting. To the author knowledge, this is the first direct method for steadystate solution with this capability. Comparison with step-by-step solutions shows a increase in performance of one order of magnitude, at least.