INFLUENCE OF PLASTIC DEFORMATION OF ADHEREND MATERIAL ON STRESS DISTRIBUTION IN ADHESIVE LAP JOINTS

Abstract

In the stress analysis of adhesive lap joints, the linear-elastic model of adherend material is often used. In some cases, when the joined material has a low yield stress, this assumption causes errors in the stress estimation in the adhesive layer or adherend. In this study, the results of numerical stress and strain analysis of adhesive lap joint were presented. In the performed analysis, both the elastic-plastic and linear-elastic models of joined materials were considered. In the first part of the study, the properties of adherend material were determined in experimental investigations. Next, the discrete model of joint was created. The results of nonlinear finite element analysis showed that for joints of materials with a low value of yield stress the plastic deformation begins in adherend at load 50% lower than destructive force of the joint. As a result of this phenomenon, the rapid stress increase in the adhesive layer is observed in an advanced phase of loading. This causes a significant decrease in strength in the lap joints of elastic-plastic materials.