Peridynamic micromechanical modeling of plastic deformation and progressive damage prediction in dual-phase materials

Abstract

In this study, a state-based Peridynamic (PD) microstructure model is developed to simulate the damage initiation and propagation and plastic deformation in multi-phase materials. The dual-phase (DP) steel is utilized as a material example. A two-dimensional PD model is developed to predict the response of three representative volume elements (RVEs) under tension static loading. RVEs are extracted from Scanning electron microscopy (SEM) images by image processing. Von Mises yield criterion with hardening is used to model plastic deformation. Failure criteria are achieved by relating PD total work needed for eliminating the interactions to the critical energy release rate. A new approach is also proposed for boundary conditions and assigning interface region properties. The failure mechanisms such as martensite cracking, ferrite, and martensite interface decohesion, are captured in the analyses. It is also found that damage initiation occurs in narrow cross-section of martensite grains, ferrite/martensite interfaces, and trapped ferrite phases. The predicted deformations, stress-strain curves, and damage patterns are also compared with the available experimental results. It is shown that the achieved results are in good agreement with the experimental results.