单搭拉剪胶焊接头的应力和刚度分析

Stress and Stiffness Analysis for Wele-Bonding Single-lap Joints

胶焊复合连接技术兼具胶接和点焊的优点,它因提高结构强度和刚度而使车辆轻量化成为可能。以胶接理论为基础,考虑了被粘体剪切应变,将焊点视为大剪切弹性模量胶粘剂,胶层和焊点沿其厚度方向的剪应力不变,建立了胶焊单搭拉剪接头的线弹性应力解析模型。在应力模型基础上,将接头各组成部分看作是独立承载的拉伸和剪切弹簧单元,得到了其刚度解析模型。应力模型中的正应力和剪应力与有限元解吻合得较好,证明理论模型正确,参数研究中确定了影响胶焊单搭接头应力分布特征的关键耦合参数。

As an advanced hybrid joining technology combining spot-welding with adhesive-bonding, weld-bonding enables to increase the joint strength and stiffness to satisfy the requirement of lightweight vehicles. The stress and stiffness models of a single-lap joint are developed based on the linear elasticity theory considering the adherend shear deformations. The spotweld in the weldbonded joint is regarded as the adhesive with large shear modulus. The assumption of linear shear stress distributions through the thickness of the adherends is adopted in the shear model, and the shear deformations in the adhesive/weldspot are assumed as constant across individual thickness. In the stiffness analysis, each component of the joint is simplified as separate tensile and (or) shear spring elements and, therefore, each sustained different levels of deflection. The shear stress along the overlap and longitudinal normal stress of the upper adherend in the analytical solutions are obtained and compared with the numerical solutions determined by the two-dimensional finite element method. The numerical experiment shows that the results of the theoretical and the FEA models agree with well. Finally, the relevant key parameters are identified and discussed.