Numerical Investigation of Stress Field for Anisotropic Elastic Bonded Joints

Abstract

In recent years, intelligent or smart structures and systems have drawn more and more attention. Bonded structures are playing a key role as active components in many fields of engineering and technology. Mechanical stress occurs in smart structures for mechanical or thermal loading. The stress concentrations caused by mechanical or thermal loads may lead to crack initiation and extension, and sometimes the stress concentrations may be high enough to debond the material parts. Reliable service lifetime predictions of bonded components demand a complete understanding of the debonding processes of these materials. The stress fields are one of the main factors responsible for debonding under mechanical or thermal loading. Stress singularity frequently occurs at a vertex in an interface of joints due to discontinuity of materials. Stress singularity is related to debonding and delamination at interface of the bonded joints. Different numerical methods had developed for determining the stress field in a 3D dissimilar material joint. Several studies have investigated the stress field in 3D elastic materials. Recently, some researchers proposed the solution of singular stress field and its stress intensity factors of an interfacial corner of a 2D dissimilar anisotropic material joint with crack. However, the stress field at a vertex in 3D anisotropic elastic bonded joints has not been made clear. In this study, the stress field at a vertex and interface edge has been investigated in anisotropic bonded joints.

The project was focused on the reliability of anisotropic elastic bonded joints under varying tensile load condition. In the present work, the displacement and stress distributions at the vertex and along the interface edge of the joint were determined using Autodesk Simulation Mechanical 2015 software. The activities of the project involve the use of advanced numerical techniques based on Finite Element Method (FEM). The stress field in anisotropic elastic bonded joints with different materials condition was calculated. The stress and displacement field near the vertex and interface edge was investigated using developed model and material combination. Finally, the numerical results were analyzed. The numerical results suggest that the displacement and stress distribution at the vertex and interface edge were larger than the inner portion of the joints. Therefore there is a possibility of delamination and debonding occurs near the vertex and free edge of the interface of bonded joint due to higher stress concentration.