Thermal Stress and Interface Delamination of Adhesive Butt Joints with Circular Hole Defects and Fillers under Uniform Temperature Changes.

Abstract

Thermal stress distributions in adhesive butt joints under uniform temperature changes are analyzed using a two-dimensional finite element method. The effects of hole defects and fillers in the adhesive layer on the stress singularity and the delamination growth at the edge of the interface are examined and the amount of delamination growth is predicted using the tensile stress near the edge of the interface. Photoelastic experiments are carried out at room temperature. The delamination growth is measured by a scale when the joints are cooled stepwise. A fairly good agreement is seen between the measured values and the predicted results for the delamination growth and between the results of the photoelastic experiments and the analyses. As a result, it is shown that the hole defects reduce the delamination growth but the effect of the fillers on the delamination growth is small.