短切碳纤维C/SiC陶瓷基复合材料的动态力学性能研究

对三种不同短切碳纤维体积含量(16%、21%、24.8%)的C/SiC复合材料利用分离式霍普金森压杆(SHPB)装置进行了常温下的冲击力学试验。根据不同应变率下的试验结果分析了其动态破坏强度和应变率效应的关系,阐明了其破坏机理。实验结果表明:三种短切碳纤维体积含量的C/SiC陶瓷基复合材料的动态应力-应变曲线光滑无震荡,且具有一定的自相似性。在近似平均应变率下,当短切碳纤维体积含量的不断提高,则C/SiC复合材料的破坏程度不断降低,整体性越来越好,说明短切碳纤维体积含量的提高对C/SiC复合材料的强度有着积极的作用。

Study on Dynamic Mechanical Properties of Short Carbon Fiber C/SiC Ceramic Matrix Composites

The dynamic mechanical tests of the C/SiC composites with three different volume fractions of short carbon fiber (12%, 21%, 24.8%) are carried out by the split Hopkinson pressure bar (SHPB), according to the test results under different strain rates to analyze the relationship between dynamic breaking strength and strain rate effects and to clarify the mechanism of its destruction. It is indicated through analysis that the dynamic stress-strain curves of the C/SiC composites with three different volume fractions of short carbon fiber were smooth, without shocks and have a certain self-similarity. At the same similar average strain rate, the extent of damage of C/SiC composite is decrease when the volume fraction of short carbon fiber continues to improve. The overall of the composite is getting better and better. It means that volume content of short carbon fiber have a positive effect on increased the strength of the C/SiC composite.