Damage growth in multiphase composites subjected to thermo-mechanical fatigue loading based on phase field method

Abstract

Engineered materials such as particle composites, due to their intricate internal structure exhibit complex damage profiles. In this work, we employ the phase field method to numerically study the damage initiation and subsequent propagation in particle composites when subjected to mechanical and combined thermo-mechanical cyclic loading. The framework is implemented in Abaqus using user elements. Two different types of particles are considered, viz., stiff and compliant particles. The influence of mean load, elastic mismatch ratio and fracture toughness between the constituent materials are systematically investigated under thermo-mechanical cyclic loads. From the numerical study, it is inferred that: (a) the number of crack nucleation sites are directly linked to the reduction in the stiffness of the complaint phase and (b) damage is more pronounced in the case of a symmetrically inverting cycle. Furthermore, under thermal cycling, the stiff phase attracts the crack when the particles have higher thermal expansion compared to the matrix.