Stress Analysis and Fracture Mechanics of Adhesive Joints

Abstract

The initiation and propagation of a crack in the structural joints is a significant problem of intense debate. There have been a number of a experimental studies which characterise the toughness of adhesive joints, based on the fracture mechanics [1,2]. The most common type of fracture toughness test was a double cantilever beam (DCB) specimen. However, the double torsion (DT) specimen, which was originally applied to study the toughness of polymer solids, has advantages compared with DCB specimen, in that specimen geometry is simple, and loading is in compression avoiding problems of gripping the specimen. An approximate linear compliance at various crack lengths is conducive to producing stable crack growth at a constant stress intensity factor. However, there has been little effort expended in using the DT specimen to study the fracture toughness of adhesive joints, except for the work of a few investigators [3,4,5].