Evaluation of the plastic zone in an elastic-plastic dissimilar materials joint

Abstract

In a dissimilar materials joint very high stresses develop near the free edge of the interface, even for low mechanical loading or after a homogeneous change of temperature, due to the different mechanical properties and different thermal expansion coefficients of the joined components. If one or both materials in the joint exhibit plastic material behaviour, after a small loading plastic deformation occurs. The aim of this paper is to find the relationship between the size and shape of the plastic zone, the loading, the material properties of the joined components and the geometry of the joint. For mechanical loading some empirical equations have been found to evaluate the size and shape of the plastic zone, based on the pure elastic stress analysis. The size and shape of the plastic zone calculated with the empirical equations are in good agreement with those from the Finite Element Method (FEM). The stress distributions in the elastic and elastic-plastic material are presented as well.