A damage evolution equation of particle-filled composite materials

Abstract This paper studies the damage process induced by microcracks in particle-filled composite materials. The damage variable D is derived from the analysis of the microcrack system and is a function of microcrack size and density. The damage evolution equation is determined by the extending and nucleating rate of microcracks. From the proposed model of the microcrack evolution process, an explicit form of damage evolution equation which is a function of stress field is given. The cracking event N and its rate N , the new crack surface area D ΔA formed by microcrack extension and its rate D ΔA are defined. The rationality of our model has been confirmed by acoustic emission tests.