复合材料单钉接头疲劳累积损伤破坏分析

Fatigue progressive damage analysis of single fastener joints in composite laminates

基于时间增量原理,推导了层合板接头疲劳加载累积损伤应力-应变分析的虚功方程。同时,引入Hashin三维疲劳失效准则进行材料的损伤判定,并结合建立的疲劳加载材料退化模型、4种基本损伤机制相互关联作用的材料性能退化方法及复合材料接头最终失效判据,建立了层合板接头疲劳载荷作用下三维累积损伤分析的寿命预测方法。最后,对层合板接头拉-拉疲劳载荷作用下的损伤累积扩展与失效规律进行了仿真分析,并与试验结果进行了对比,结果表明:本文中建立的寿命预测方法能够很好地预测层合板接头的寿命以及损伤发生、扩展及最终失效。

The equations of virtual work based on the theory of time increment were deduced to analyze stress - strain states under fatigue loading conditions. A progressive damage method of predicting the fatigue life of mechanically fastened joints in fibrereinforced plastics was established, which is integrated fatigue material property degradation models. The three-dimensional Hashin-type fatigue failure criteria were introduced into the method to detect damage for diverse damage modes. The criteria of the structure catastrophe and the sudden material property degradation rules including the correlation among four basic damage mechanisms were also established. The fatigue life, failure initiation, propagation and catastrophic failure of composite bolted joints under tension-tension fatigue loading conditions are predicted by using the fatigue progressive damage method established in the paper. Excellent agreement is found between data obtained from this study and the experiment.