A multi-phase linear kinematic elastoplastic model for the HAZ of welded S355J2 steel under low-cycle fatigue

The aim of this paper is to develop a linear kinematic elastoplastic model for simulating the mechanical behavior of a heat-affected zone under low-cycle fatigue for welded S355J2 low-carbon steel. First, an experimental procedure is developed by means of a Gleeble machine for creating macroscopic tensile specimens with different homogeneous metallurgical compositions according to a welding continuous cooling transformation diagram. Then, cyclic tensile tests are carried out by prescribing different strain amplitudes up to 1%. By considering the stabilized behavior at mid-life, the yield stress and hardening modulus are identified as functions of the metallurgical composition by means of a linear mixture rule. Comparisons with numerical simulations are presented to show the efficiency of the multi-phase cyclic linear kinematic elastoplastic model proposed in this work.