A Research on Strength Characteristics of Compact Tension Specimens with Heterogeneous Composite Materials Bonded by Adhesives

Abstract

With CT specimen models of CFRP with cracks and adhesive interfaces, this study aims at investigating the strength characteristics of heterogeneous composite materials bonded by adhesives through the analyses. Even minor cracks or defects that may occur inside a composite material in the manufacturing process can result in the stress concentration, and this will lead to the material breakage. So, we designed CT specimen models with CFRP alone and CFRP with stainless steel or aluminum by using their material properties of CFRP, stainless steel, and aluminum. The simulation analyses were carried out and their strength characteristics were investigated. It is necessary to prepare a way to relieve stress concentration at the stage of design under the assumption those cracks actually occur at manufacturing process. By combining CFRP with stainless steel or aluminum, both of which have good ductility, we found that the deformation and deformation energy increased and the maximum equivalent stress decreased. It is thought that this material can lower the risk of material breakage by changing some of the impact energy which may damage CFRP, into the deformation energy. This deformation energy brings about the good ductility by utilizing stainless steel and aluminum under the situations where the sudden tension and impact loads are expected or applied. The results revealed that when CFRP was combined with the heterogeneous metal, it was possible for CFRP to be used where otherwise it could not be used alone and provided CFRP with better material property and more diverse process-ability So, this composite material can be prevented from breakage in the process of manufacturing and increase the safe use. As CFRP with the rigidity better than metals can be applied to composites, the composites with CFRP can be improved to have better material property and more diverse process-ability