复合材料-金属毛化接头的失效预测模型

A MODEL FOR FAILURE PREDICTION OF A COMPOSITE-METAL-WELD JOINT

针对复合材料与金属连接的一种新型连接形式-毛化接头,建立了其在拉伸载荷作用下的失效模式与破坏载荷的宏-细观预测模型.首先根据毛刺的分布选择合适的代表体积元,建立毛刺层单胞模型,施加周期性边界条件,通过有限元分析得到毛刺层的平均刚度参数.其次,基于累积损伤理论预测毛刺层的单胞强度,分析毛刺层的失效机理.最后,将毛刺层的等效材料参数赋予接头整体模型,预测接头的抗拉强度及失效模式.预测结果与试验值吻合良好.分析结果表明,毛化接头的承载能力和失效模式与毛刺的密度高度、搭接面积等因素密切相关,通过参数设计可获得较高的承载能力.

A macro-micro model for predicting the strength and failure of Composite-Metal-Weld（CMW）joints subjected to static tensile loading was developed in this study.According to the distribution of protrusions,a suitable representative volume element（RVE）was selected and the unit cell model of the protrusion layer was established,with an unified periodical boundary con-dition being applied to it.The average stiffness of the protrusion layer was obtained by finite element method（FEM）.The strength and failure modes of the unit cell were analyzed based on the cumulative damage theory.Equivalent material parameters of the protrusion layer were then applied to the whole model to obtain the tensile strength and failure mode of the CMW joints.The results show that the strength and failure mode of the CMW joints are affected by the density and height of protrusions,lap size of the joints and so on.The CMW joints could have higher strength by choosing some optimized parameters.