A new fracture mechanics model for multiple matrix cracks of SiC fiber reinforced brittle-matrix composites

A new model is proposed for multiple matrix cracking in order to take into account the role of matrix-rich regions in the cross section in initiating crack growth. The model is used to predict the matrix cracking stress and t he total number of matrix cracks. The model converts the matrix-rich region s into equivalent penny shape crack sizes and predicts the matrix cracking stress with a fracture mechanics crack-bridging model. The estimated distri bution of matrix cracking stresses is used as statistical input to predict the number of matrix cracks. The results show good agreement with the exper imental results by replica observations. Therefore, it is found that the ma trix cracking behavior mainly depends on the distribution of matrix-rich re gions in the composite. (C) 1999 Acta Metallurgica inc. Published by Elsevi er Science Ltd. Ali rights reserved.