Ductile damage analysis under extreme low-cycle biaxial shear loadings: Experiments and simulations

This paper addresses the experimental and numerical analysis of ductile damage under extremely low-cycle loading conditions with a large strain range. Shear cyclic loading stress states with stress triaxiality of approximately zero are generated using the biaxially loaded cruciform X0-specimen, with equal positive and negative forces applied to different loading axes. Monotonic and various symmetric cyclic loading patterns are designed to investigate the influence of loading histories on the material response at both macro- and micro-levels. The numerical calculations are performed using a novel anisotropic continuum damage model. For plasticity, the hydrostatic sensitivity Drucker–Prager yield condition with combined hardening is used to characterize the isotropic plastic behavior. Additionally, an anisotropic damage strain tensor that considers stress state influences is used to predict the occurrence and development of damage. Digital image correlation (DIC) technique and scanning electron microscopy (SEM) technique enable comparison of experimental and numerical results in different aspects. The numerical results for load–displacement curves, total strain field, and damage strains agree well with the experimental data, as confirmed by quantitative error analysis in load–displacement curves and statistical analysis of SEM images.