玻璃基复合材料基体裂纹行为和分布规律的研究

Crack Behavior and Distribution in Matrix of the Glass Matrix Composites

碳化硅纤维增强玻璃基复合材料是一种能够在1100℃高温氧化环境中使用的新型材料。玻璃基复合材料承载后基体产生裂纹，裂纹影响了材料的力学性能。本文改进了实验方法，使用不同加载──卸载循环后试样表面的照片研究了裂纹分布规律，发现裂纹的行为在同一材料，同一加载后，不同区域内有所不同，分为门槛和增长两种类型。在门槛区内，经一定的载荷后，裂纹突然出现，布满全部区域。在增长区内，裂纹随载荷的增加而逐渐增加。本文给出了裂纹分布规律，并分析了影响裂纹发展规律的主要原因是纤维分布的均匀性。

SiC fiber reinfereed glass matrix compeites have ben inveshgated as a potetial new matertial to be used in oxidizing envirornments at temperature of 1 100℃. Afte a load case, the cmeks will appear in matrix area of the composite,whch will influence the mechanical properfties. The experimental method was improved, and photographs of polished speimens were mads to observe the crack behavior after different load-unload cycles. Two types of crack growth behaviors in differmt regions, the threshold mode and the growth mode , were observed in the same specimen and after thesame load. After the load case, the cracks in threshold region will appear quickly and fill in full region,but other cracks in growth region will incresae gradually with load. The crack distributions in threshold and in growth regions , and the analysis of influence factor on two behaviors,which is caused by the distribution of fibers in the comisites are given in this paper.