Stress distribution of adhesively bonded double lap joints in FRP laminated composites using FEM

Abstract

Adhesively bonded joints are increasingly being used in joining various structural components made of FRP laminated composites. Adequate understanding of the behavior of adhesively bonded joints is necessary to ensure efficiency, safety and reliability of such joints. While single lap joint has received considerable attention, very little work has been carried out on the double lap joint configuration. The present investigation deals with the static analysis of adhesively bonded double lap joint in laminated FRP composites using three-dimensional theory of elasticity based finite element method. The finite element model is validated with the theoretical concepts. The double lap joint made of generally orthotropic laminates subjected to longitudinal loading is analyzed. The out-of-plane normal and shear stresses are computed at the interfaces of the adherend and adhesive, and at mid surface of the adhesive for different ply orientations in the double lap joint are considered for the analysis. It was predicted that when the fiber angle increases the stiffness of the plate in the longitudinal direction decreases and the interlaminar stresses at joint interfaces increases due to the effect of coupling and also the longitudinal displacement increases.