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通过试验研究了预紧力、齿长、荷载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规律。试验结果表明:CFRP预紧力单齿接头的疲劳极限承载值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,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接头静承载力随齿长增加而升高,但是在相同荷载水平下增加齿长不一定可以提高接头的疲劳寿命,尤其在低荷载水平下齿长增加反而降低了疲劳寿命;PTSTC在加载初期疲劳裂纹快速萌生,之后扩展缓慢,在接近破坏前的几次循环中又骤然增大,预紧力可以抑制疲劳损伤的累积速率;疲劳过程中PTSTC的刚度衰退不明显,在寿命前95%阶段仅下降1%~4%,预紧力也可以抑制刚度的衰退速率。研究成果可为复合材料连接接头抗疲劳设计提供参考依据。
The influence of pretightening force, tooth length and load level on the static and fatigue properties of carbon fiber reinforced resin matrix composite (CFRP) pretensioned single tooth joint (PTSTC) was studied through experiments. The experimental results show that the fatigue limit load of CFRP pretensioned single-tooth joint can reach 80% ~ 85% of the static ultimate bearing capacity, and the fatigue performance has some advantages compared with traditional connection methods such as bolts. The pre-tightening force can be significantly improved CFRP single-tooth joints static and fatigue properties; CFRP joint static bearing capacity increases with the increase of tooth length, but in the same load level increases the tooth length may not be able to improve the joint fatigue life, especially at low load levels increased tooth length But the fatigue life was reduced. The fatigue crack initiation rate of PTSTC increased rapidly at the initial stage of loading, and then expanded slowly. After a few cycles before the failure, PTSTC suddenly increased. The prestressing force could suppress the cumulative rate of fatigue damage. The fatigue strength of PTSTC The recession is not obvious, 95% of the stage before the life expectancy decreased by only 1% to 4%, preload can also inhibit the stiffness of the recession rate. The research results can provide reference for anti-fatigue design of composite connector.