Stress analysis of composite adhesive bonded joints under incipient failure conditions

Abstract

Composite structures with their remarkable properties often require assembling different components and repairing the damaged regions by employing mechanical or adhesive bonding joints. Among the bonding techniques, adhesive bonding is considered the most diffused and efficient method.Analysis of stress distribution that develops in the joint is a crucial field of research to put effort with the aim to develop engineering strength criteria. Once an adhesive bonded joint is subjected to the axial tensile load, shear and peel stress intensification takes place at the ends of the overlap. With regard to the literature, it can be concluded that there are few reliable predicting tools for brittle adhesives, for which failure usually initiates at the edge of the bonding area and propagates through the interface region. The aim of this paper is an investigation on stress field in single-lap joint (SLJ) and scarf-lap joint (ScJ) under the tensile loading. A two-dimensional numerical analysis by employing Finite Element Method (FEM) and a developed analytical solution were implemented to realize the correlation of the results. Furthermore, a comparison between possible failure criteria was performed by using FE results. Adherend thickness, overlap length, and scarf angle were considered as the joint geometry parameters. Effects of these parameters on the fracture behaviour of bonded joints were evaluated.