Three-dimensional finite element analysis of stress response in adhesive scarf joints subjected to impact tensile loads

The stress wave propagation and the stress distribution in adhesive scarf joints of similar adherends subjected to impact tensile loads are analyzed in an elastic deformation using a three-dimensional finite-element method (FEM). An impact load is applied to the joint by dropping a weight. The upper end of the upper adherend is fixed and the lower end of the lower adherend is subjected to an impact load. FEM code employed is DYNA3D. The effects of scarf angle of the adherends, the adhesive thickness and Young's modulus of the adherends on the stress wave propagation at the interfaces are examined. It is found that the maximum value of the maximum principal stress a, occurs at the interface of the lower adherend to which the impact load is applied. The effect of the adhesive thickness was found to be small on the maximum value of a, in this joint. The maximum principal stress at the interface increases as Young's modulus of adherends increases. In addition, experiments were carried out to measure the strain response of the adhesive scarf joints subjected to impact tensile loads using strain gauges. A fairly good agreement is observed between the analytical and the experimental results.