对T300碳纤维增强三维针刺碳纤维增强SiC(C/SiC)复合材料(纤维体积含量为30%)的单调和加载-卸载拉伸载荷下的拉伸行为进行了研究。结果表明:T300碳纤维增强三维针刺C/SiC复合材料的拉伸强度和断裂应变分别为129.6MPa和0.61%。单调和加载-卸载拉伸应力-应变曲线均为非线性变化,主要是复合材料中裂纹的扩展,界面相脱黏和滑移,以及纤维的逐步断裂和拔出所致,使得复合材料在拉伸载荷下呈非脆性破坏。卸载应力水平对卸载后的残余应变和再加载模量有较大影响。卸载应力小于80 MPa时,随着卸载应力的增加,残余应变线性增加,模量线性降低:卸载应力高于80MPa时,二者随着卸载应力的增加而呈二次函数快速变化。
The monotonic and load-unload tensile behaviors of three-dimensional(3D)needled T300 C/SiC composite were investi- gated.The results show that the tensile strength and strain of the 3D needled T300 C/SiC composite are 129.6MPa and 0.61%,re- spectively.The stress-strain curves of the 3D needled T300 C/SiC composite under monotonic and step tensile loads exhibit a nonlin- ear behavior,which is caused by the propagation of micro-cracks,debonding and sliding of interfaces,and gradually results in frac- turing a...