复合材料螺栓连接渐近失效分析

PROGRESSIVE DAMAGE ANALYSIS OF COMPOSITE BOLTED JOINTS

为了研究预紧力和摩擦系数对复合材料螺栓连接强度的混合影响及其机理,使用ANSYS软件建立了复合材料层合板单钉连接的三维有限元模型。采用渗透接触法来模拟螺栓的预紧力,考虑各组件之间的接触摩擦和结构二次弯曲的影响,使用改进后的三维Hashin失效准则和Camanho退化模型,对复合材料单钉连接进行渐进失效分析。数值模拟结果与文献中的实验结果吻合良好。分析结果表明,增大接触面的摩擦系数和施加合适的预紧力均能提高接头强度。摩擦系数小时,通过增加预紧力来提高接头强度的效果不明显,反而使复合材料容易发生基体开裂。在施加预紧力的同时应综合考虑摩擦系数的大小。

In order to investigate the combined influence of friction coefficient and bolt-torque on the strength of single-bolted composite joints and their mechanism,a three-dimensional finite element model of laminate in singlebolted joints has been built in ANSYS software. The bolted-torque is applied by using penetrative contact method.The influence of friction in components and secondary bending of the plates has been considered. The progressive damage analysis of composite bolted joints is implemented by using improved Hashin failure criterion and Camanho degradation model. The model is validated through comparison with experimental data in literature. It is shown that the joint strength can be enhanced by increasing the friction coefficient and applying appropriate bolt-torque. Increment in the bolt-torque cannot improve the joint strength obviously and higher bolt-torque can make the matrix crushing when the friction coefficient is small. Thus friction coefficient should be considered when applying bolt-torque. The results are instructive for engineering application.