ABSTRACT

This paper develops a numerical model that contained random lip-shaped matrix cracks based on the maximum energy release rate criterion for the prediction of failure progress of Continuous Fibre-reinforced Ceramic Matrix Composites (CFCC) under transverse tension. Fibre distribution layout is created based on the actual microstructure and the Random Sequential Adsorption algorithm is used to generate the distribution of lip-shaped matrix cracks. The influence of the lip-shaped matrix crack distribution and crack density on the failure progress and stress–strain response was investigated. It was found that the onset of damage initiation commenced from the lip-shaped matrix crack when the interface fracture energy was smaller than the critical interface fracture energy. The failure progress and the predicted results were in good agreement with the experimental results. The different matrix cracks distribution affected the failure progress. Finally, the tensile strength and the elastic modulus both decreased with the crack density increasing.

摘要

本文基于最大能量释放速率准则，建立了一个包含随机唇形基体裂纹的数值模型，以预测连续纤维增强陶瓷基复合材料（CFCC）在横向张力下的破坏过程。根据实际的微观结构创建纤维分布布局，并使用随机顺序吸附算法生成唇形基质裂纹的分布。研究了唇形基体裂纹分布和裂纹密度对破坏进程和应力应变响应的影响。已发现，当界面断裂能小于临界界面断裂能时，损伤始于唇形基体裂纹。失效进展和预测结果与实验结果吻合良好。不同的基体裂纹分布影响了失效进程。最后，抗拉强度和弹性模量均随裂纹密度的增加而降低。