Effect of the use of a hybrid material on stress reduction in an adhesive used for a single lap joint; bending loading effect

Abstract

Composite materials are increasingly widely used in high-tech industries in recent decades and are now affecting more and more fields, especially in aeronautics. Their success is due to the many advantages they offer compared to traditional materials: lightness, good resistance to fatigue, good resistance to corrosion, the possibility of obtaining complex shapes. The bonding assembly of composite materials is all the more interesting since the durability of the assemblies and essentially the adhesive joint strongly depends on the nature of the fiber as well as the stacking sequence. Therefore, the introduction of the hybrid composite in recent years brings a great advantage in the stiffness flexibility compensation of composite plates. However, the behavior of composite plate assemblies has been the concern of researchers for several years, the analysis of their behavior is generally studied in tension-shear stress, but in reality, these assemblies are subjected to different types of stress. As in the case of bending, the behavior of the adhesive is poorly understood and few studies have been conducted in this area of research. The objective of our work is to analyse by the finite element method the variation of the stresses in the adhesive joint used for the assembly of two hybrid composite plates. These hybrid composite sheets consist of alternating 0.25 mm thick aluminum sheets and carbon or unidirectional glass prepregs, bonded with an epoxy adhesive. These hybrid composites have shown their efficiency compared to the metal plate and composites by their resistance to fatigue and impact. The results of our numerical analysis show the variation of the various stresses in the adhesive joint for an assembly of hybrid composite plates type aluminum-carbon and aluminum-glass. The location of the reinforcing layers in the composite relative to the base layers was varied in order to see the optimum position for which the stresses in the glue joint are lowest under the bending test.