碳纤维增强树脂基复合材料预紧力单齿接头的静态及疲劳性能试验

通过试验研究了预紧力、齿长和载荷水平对碳纤维增强树脂基复合材料（CFRP）预紧力单齿接头（PTSTC）静态和疲劳性能的影响。试验结果表明:CFRP PTSTC的疲劳极限承载力可以达到静态极限承载力的80%~85%，与螺栓等传统连接方式相比，其疲劳性能具有一定优势；预紧力可以显著改善CFRP单齿接头的静态和疲劳性能；CFRP PTSTC的静态极限承载力随齿长增加而升高，但是在相同载荷水平下增加齿长不一定可以延长接头的疲劳寿命，尤其是在低载荷水平下齿长增加反而会缩短疲劳寿命；在加载初期，PTSTC的疲劳裂纹快速萌生，之后扩展缓慢，在接近破坏前的几次循环中又骤然增大，预紧力可以减缓疲劳损伤的累积速率；疲劳过程中PTSTC的刚度衰退不明显，在前95%疲劳寿命阶段仅下降1%~4%，预紧力也可以减缓刚度的衰退速率。所得研究成果可为复合材料接头抗疲劳设计提供参考依据。 

Tests for static and fatigue performances of carbon fiber reinforced plastics pre-tighten single tooth connector

The effects of pre-tighten force,tooth length and stress level on static and fatigue performances of car-bon fiber reinforced plastics (CFRP)pre-tighten single tooth connector (PTSTC)were investigated by tests.The test results show that the fatigue ultimate load-capacity of CFRP PTSTC reaches to 80%-85% of the static ultimate load-capacity,and comparing with traditional connection methods such as bolt connection etc.,the fatigue perform-ance of it has advantages at some degree.The pre-tighten load can improve the static and fatigue performances of CFRP single tooth connector significantly.The static ultimate load-capacity of CFRP PTSTC increases with the tooth-length increasing,but increasing the tooth-length would not necessarily improves the fatigue life of the connec-tor under the same load level,especially,the fatigue life reduces with the tooth-length increases under lower load level.The fatigue crack of PTSTC initiates rapidly during the early loading period,then grows slowly,and propa-gates sharply again in the last few cycles before fracture.The pre-tighten load can slow down the fatigue damage ac-cumulation rate.The stiffness degeneration during fatigue process of PTSTC is not obviously,which is only 1%-4%in the former 95% of the fatigue life.The pre-tighten load can also slow down the stiffness degeneration rate.The investigation conclusions obtained can provide references for the anti-fatigue design of composite connector.