Thermodynamically consistent formulation coupling crystal plasticity theory and Johnson-Cook damage model to simulate micromachining of copper

Abstract

In this work, a microstructural-related model was developed to simulate micromachining of FCC polycrystalline copper. Indeed, a crystal plasticity framework was adopted to describe the anisotropy of the mechanical behavior. Some material microstructure characteristics (such as grain size, grain misorientation and crystallographic orientation) are explicitly considered through the constitutive model. For describing the material removal during chip formation, a modified thermodynamically consistent formulation of the Johnson-Cook damage model was used. The model was implemented in the ABAQUS/Explicit finite element solver with a user-defined subroutine, and the experimental validation was performed using data on the cutting forces available in the literature. Finally, the model was used to investigate the effect of the microstructure on the micro-machining cutting forces and chip formation process. According to the results, the proposed model allows capturing the cutting forces trends due to the crystallographic anisotropy.