Crack Propagation and Prediction of Strength for Adhesive-bonded Joints/Structures using Finite Element/Analysis.

An analytical investigation was performed to study the strength of adhesive-bonded joints/structures based on the fracture mechanics approach considering crack propagation using a three dimensional linear finite element analysis. An analytical model was developed and a virtual crack closure technique was applied to obtain total strain energy release rate. The distribution of total strain energy release rate at a crack front of adhesive-bonded joints/structures were calculated. The initial location of a crack and the crack geometry in the adhesive layer could be predicted from the distribution curve of total strain energy release rate. The strength of adhesive-bonded joints/structures, whose geometry was arbitrary, could be estimated using the R-curve method, here the crack length was measured along the crack propagation path from the crack initiation. The proposed approach was well confirmed by the experiments.