Effect of Adherend Material Stiffness and Geometrical Stiffness on Strength of Adhesively Bonded Joints.

Abstract

The effect of adherend stiffness on the joint strength is examined by varying the adherend material and varying aspect ratio of the adherend dimension. The joint type used in this study is a stepped-lap bonded joint. The joint materials are three kinds of metals, carbon steel, brass and aluminum alloy, for the adherends and an epoxy resin for the adhesive. The relationship between the Young's modulus of the adherend material and strength of the joint is experimentally investigated. The joint strengths, i.e., initial failure strength and final fracture strengh are predicted by applying our adhesion criteria on a proposed FEM model. Both upper and lower bounds on the predicted final fracture strength is obtained. And these predicted strengths show good agreement with the experimental results.