Finite element modeling of debonding behavior of the adhesively bonded joints between sandwich panel and pultruded profile in flexural loading

The strength of adhesively bonded joint plays very important role on the behavior of loaded composite structures. In the present paper debonding behavior of the adhesive joint between sandwich panel and pultruded profile is investigated by the finite element method. Cohesive zone model and contact elements are used in order to simulate the adhesive joint between stiffener and the panel. Representing the adhesive material, an embedded layer is modeled between the sandwich panel and profile. The effects of geometrical parameters including the thickness of the adhesive layer and profile on the behavior of joint are investigated. Moreover, the effect of initial defect in the adhesive joint on the debonding results is studied. The results present that in the prefect bonding, increasing in the thicknesses of the profile and adhesive layer improves the joint behavior against debonding. However in defected joint, increasing the profile thickness decreases the debonding load and presence of initial defect decreases the debonding load by 51%. The results also show that presence of embedded adhesive layer has positive effect on the debonding behavior of the joint. Initial debonding load without adhesive layer decreases by 40% in comparison with the joint containing 10 mm adhesive layer.