Steady-state limit analysis of elastoplastic trusses under cyclic loads

Abstract

For elastoplastic trusses under cyclic loads, a method is presented for finding the steady-state limit, which bounds convergence and divergence of plastic deformations. Using Taylor-series expansion, a new incremental theory is formulated for tracing the sequence of steady states generated under an idealized cyclic loading program with continuously increasing amplitude. The sequence is regarded as a continuous path. The steady-state limit is found as the first limit point of the continuous path. Geometrical and material nonlinearities are taken into account using the Total Lagrangian formulation and the bi-linear kinematic hardening rule. Validity of the proposed method is shown through numerical examples.