Effects of thin adhesive layer and riveted-pitch distance on the stress concentration factor of riveted lap joints

Abstract

This research is to study the effects of the adhesion of thin adhesive layers in terms of modulus, and the riveted-pitch distance on the stress concentration factor (SCF) of riveted lap joints, when the joints are subjected to static tensile loading using Finite Element Method (FEM). The methodology comprises of three tasks. The first task is to perform tensile and simple shear tests of thin adhesive layers to determine the adhesion of adhesives in terms of modulus, which will be used in finite element models. The second task is to verify the finite element models by testing the stiffness of riveted lap joints. The third task is to vary the adhesion of thin adhesive layers and the riveted-pitch distance in finite element models, and then study the effects of these two variables on SCF at the rivet-shank hole. It is found that SCF is reduced when the adhesion of thin adhesive layers is increased. The increase in the adhesion reduces bending of the joints, resulting in the reduction of stresses at the rivet-shank hole. In addition, it is also found that SCF is reduced when the riveted-pitch distance is decreased. When the two variables are considered together, it is found that the riveted-pitch distance does not affect SCF when the adhesion of thin adhesive layers is 10 MPa or higher.