Removal mechanism and damage evolution of SiCp/Al composites based on FEM-MD model considering 3D random polyhedral particles in orthogonal cutting
Ming Li, Qingguang Li, Xianchao Pan, Jiaqi Wang, Zixuan Wang, Shengzhi Xu, Yunguang Zhou, Lianjie Ma, Tianbiao Yu
Abstract
This study investigates the cutting mechanism and particle damage evolution of SiCp/Al composites using a coupled FEM-MD modeling approach. A Python-based algorithm was developed for generating representative volume element (RVE) through stochastic convex polyhedron modeling, enabling geometrically faithful reconstruction of particle morphologies. At the micro-scale, molecular dynamics simulations calibrated the cohesive zone model parameters for Al–SiC interface, while meso-scale finite element modeling incorporated these MD-derived interfacial properties to establish particle-matrix interaction dynamics. Orthogonal cutting simulations systematically revealed three speed-dependent material removal regimes: 1) Low-speed (<200 mm/s) particle extraction inducing matrix tearing through interfacial debonding; 2) Medium-speed (200–400 mm/s) extrusion-dominated fragmentation generating angular debris; 3) High-speed (>400 mm/s) impact-induced comminution producing refined fragments that minimize surface damage. The polyhedral particle model demonstrated superior predictive accuracy over spherical approximations, particularly in capturing edge-driven stress concentrations and anisotropic debonding patterns. Experimental validation confirmed the multi-scale model's predictive accuracy for machining-induced surface damage. This study extends multi-scale modeling methodologies for composite machining by uniquely integrating Python-based stochastic geometry reconstruction with MD-calibrated interfacial mechanics, providing a systematic framework for studying the damage mechanism of SiCp/Al composites machining.