Abstract：This study aims to analyze the elastoplastic characteristics of DP steels under complex loading conditions. The three-step tensile tests associated with stain path change were proposed and conducted. The comparison of mechanical behaviors such as degradation of elastic modulus, anisotropic hardening and permanent softening between monotonic cyclic loading and non-coaxial loadings were performed and analyzed. The results show that the transient anisotropy hardening behavior of the materials at the initial stage of reloading is related to the strain path. The increase of reloading angle, pre-strain magnitude, or martensite content can exacerbate permanent softening of the materials. Meanwhile, the evolutions of elastic modulus of DP steels under different loadings were compared. It is found that the degree of elastic modulus degradation also rises with the increase of reloading angle, pre-strain magnitude, or martensite content. In addition, the results indicate that the evolution of elastic modulus degradation under complex loading path changes is more significant than that under monotonic cyclic loading.
2021, Vol. 42 
