The effect of inclusions embedded in the adhesive on the stress distribution and strength of single-lap adhesive joints: analytical and numerical analysis

Abstract

In this study, an analytical analysis and a finite element method (FEM) study of the overall strength and interfacial stress distribution of single lap joints with an embedded inclusion in the adhesive layer were performed. The stress analysis model for the single lap adhesive joints including inclusion layers was firstly established, and the effects of the thickness and stiffness of the inclusions on their mechanical strength were discussed in detail. The results show that the bond strength of the adhesive joints is highly dependent on the geometric parameters and properties of the inclusions, and increases with the inclusion thickness and stiffness. When the stiffness of inclusions is lower than that of the adhesive layers, their introduction degrades the bond strength of the single lap adhesive joints. The interface stress distribution and failure mechanism caused by the inclusion layers are intuitively analyzed by FEM, which is in good agreement with the analytical analysis.