Three-Dimensional FEM Stress Analysis and Strength Evaluation of Scarf Adhesive Joints under Static Bending Moments

Abstract

The stress distributions at the interfaces in the scarf adhesive joints under static bending moments were analyzed using two-dimensional and three-dimensional finite element calculations. The effects of the scarf angle, adhesive Young's modulus and the adhesive thickness on the interface stress distributions were examined. It was found that the singular stress at the edges of the interfaces decreased as the adhesive Young's modulus increased and the adhesive thickness decreased. The singular stress at the edge of the interfaces obtained from the 3-D was found to be larger than that from the 2-D FEM. The bending moment when the joint was ruptured was also predicted using elasto-plastic FEM calculations. For verification of the FEM calculation results, the strains on the adherends and the bending moment when the joint was ruptured were measured. The measured results of the strains and the bending moment when the joint was ruptured were fairly consistent with the results obtained from the 3-D FEM calculations.