Mechanical behavior of low carbon steel subjected to strain path changes: Experiments and modeling

The mechanical response of a low carbon steel under complex strain path changes is analyzed here in terms of dislocation storage and annihilation. The mechanical tests performed are cyclic shear and tensile loading followed by shear at different angles with respect to the tensile axis. The material behavior is captured by a dislocation-based hardening model, which is embedded in the Visco-Plastic Self-Consistent (VPSC) polycrystal framework taking into account the accumulation and annihilation of dislocations, as well as back-stress effects. A new and more sophisticated formulation of dislocation reversibility is proposed. The simulated flow stress responses are in good agreement with the experimental data. The effects of the dislocation-related mechanisms on the hardening response during strain path changes are discussed. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.