考虑分层损伤的复合材料螺栓连接强度预测与损伤分析

Strength Prediction and Damage Analysis of Bolted Composite Joints Based on a Delamination Damage Model

针对传统复合材料损伤分析方法未考虑界面层的损伤问题,基于三维累积损伤分析方法和内聚力模型方法,建立一套能够综合考虑面内损伤和层间损伤的复合材料螺栓连接数值分析模型。通过对两种典型复合材料单钉接头进行强度分析,表明该计算方法比传统有限元方法具有更高的精度。基于该模型,对接头层合板的分层扩展以及拧紧力矩对接头强度和分层扩展的影响进行研究。结果表明:分层扩展方向和层合板断裂方向是一致的;拧紧力矩对连接强度有明显提高作用,并且对孔边分层扩展有抑制作用。

Countered at the traditional damage analysis of composite without considering the interlaminar failure,based on the three-dimensional progressive damage analysis and cohesive zone model method,a new progressive damage model capable of numerically simulating the behavior of bolted composite joints comprehensively considering composite layer and interlaminar failure is developed.Through the strength analysis of two typical composite single fastener joints,it shows that the results by new model better agree with the experiments than by the traditional FEM progressive damage model.By this model,a study of the delamination propagation of the composite joints and the effect of tightening torque on the strength of composite joints and delamination propagation is performed.It is found that the direction of delamination propagation is the same with the orientation of fracture.The tightening torque increases the strength of composite joints obviously and can suppress the delamination propagation at hole in composite joint.