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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。
Tensile behavior of T300 carbon fiber reinforced three-dimensional acupuncture carbon fiber reinforced SiC (C / SiC) composites (fiber volume content of 30%) under monotonic loading-unloading tensile load was studied. The results show that the tensile strength and fracture strain of T300 carbon fiber reinforced three-dimensional needle-punched C / SiC composites are 129.6MPa and 0.61% respectively. The monotonic and loading-unloading tensile stress-strain curves are all non-linear changes mainly due to the crack propagation in the composite, the debonding and slipping of the interface and the gradual fracture and pull-out of the fiber, Tensile load was non-brittle failure. Unloading stress levels have a greater impact on residual strain and reload modulus after unloading. When the unloading stress is less than 80 MPa, the residual strain linearly increases and the modulus decreases linearly with the unloading stress increasing. When the unloading stress is higher than 80 MPa, the residual stress changes quadratically with the unloading stress increasing.