Numerical simulation and experimental study on mesomechanics properties of particulate composites

Abstract

AbstractAt present, it exists the problems of poor computational accuracy of the micromechanical model and insufficient adaptive matching of the RVE unit cell model boundary conditions, being caused by the random distribution of particle size and quantity in particle composite materials. As for the above problems, the paper proposes a micromechanical model that uses a random sequence adsorption algorithm to deeply match and enhance the random distribution of particles, and a subroutine joint simulation method to generate boundary conditions quickly and automatically. The RVE unit cell model of particulate composites are numerically simulated at the micromechanical level. It was found that the enhancement of the mechanical properties of the base material by enhancing particles is highly consistent with the actual improvement value. The simulation values and actual values of particle composite materials with different volume contents are also accurately consistent. In addition, with the increase of particle volume content, its reinforcement effect on the base material first increases and then decreases, and there exists an optimal mixing ratio and a minimum mixing ratio. The optimal mixing ratio for short cut fiber reinforced particles is 50%, with a minimum mixing ratio of 10%. The optimal mixing ratio for silicon carbide reinforced particles is 40%, with a minimum mixing ratio of 8%. Through experimental results, it has been verified that the micromechanical model can quickly and accurately predict the elastic constants and Poisson's ratio of composite materials under periodic displacement boundary conditions, with a prediction accuracy of within 10%.Highlights Effectively solve the problems such as the random distribution of the size and quantity of reinforced particles in the particle composite material and the difficulty in adding the boundary conditions of the micro‐RVE unit cell model in the macro composite material. A random sequence adsorption algorithm is proposed to generate the RVE cell model with reinforced particles, and the periodic displacement boundary conditions are added to the RVE cell model through Python and Abaqus joint simulation. The simulation results show that the stress of chopped fiber reinforced particles is about 1.96 times that of the matrix material, and the stress of SiC reinforced particles is about 2.1 times that of the matrix material, and the optimal mixing ratio of chopped fiber reinforced particles is 50% and that of silicon carbide reinforced particles is 40%. The proposed micromechanical model can accurately predict the elastic constants of composites under periodic boundary conditions, and its prediction accuracy can be controlled within 10%. In this paper, a more reasonable meso‐stress‐strain field of single cell element is given, which can provide reference for studying the meso‐failure mechanism and nonlinear mechanical behavior of particle composites.