Three-dimensional Finite Element Analysis of Stress Response in Adhesive Butt Joints Subjected to Impact Tensile Loads

Abstract

The stress wave propagation and the stress distribution in adhesive butt joints of similar adherends subjected to impact loads are analyzed using a three-dimensional finite-element method (FEM). The code employed is DYNA3D. An impact load is applied to a joint by dropping a weight. An adherend of a joint is fixed and the other adherend to which a bar is connected is impacted by the weight. The height of the weight is changed. The effect of Young's modulus ratio between the adherends and the adhesive, the adhesive thickness and the geometry of T-shaped adherends on the stress wave propagation at the interfaces are examined. It is found that the maximum stress is caused at the interfaces of the adherend subjected to an impact load. In the case of a T-shaped adherend, it is seen that the maximum stress is caused near the center of the interfaces and that it increases as Young's modulus of the adherends increases. In the special case where the web length of the T-shaped adherends equals the interface length, it is seen that the singular stress occurs at the edge of the interfaces and it increases as Young's modulus of the adherends decreases. The maximum principal stress increases as the adherend thickness increases. In addition, the strain response of adhesive butt joints subjected to impact loads was measured using strain gauges. A fairly good agreement is found between the numerical and the measured results.