The effect of composite orientation on the mechanical properties of hybrid joints strengthened by surfi-sculpt

Abstract

Advanced hybrid joints strengthened by surfi-sculpt (manufactured by electron beam surfi-sculpt (EBS)) have been developed to address the challenges in joining fibre reinforced polymer (FRP) composites to metals. In the present work, the effect of composite orientation on the mechanical properties of the joints is experimentally studied. In the study, the thickness of the composite adherend is kept constant and the volume content of ±45° ply is increased from 11.1% to 88.9%. Joints without surfi-sculpts are manufactured as reference joints. The result indicates that surfi-sculpt is able to delay the damage initiation and improve the joints ultimate failure load, failure strain, and absorbed energy. Composite orientation is able to vary joints mechanical properties significantly. With the volume content of ±45° ply increase, joints damage mechanisms change from bare composite matrix crush to the combination of surfi-sculpts bending, surfi-sculpts breakage and composite compression. With optimum composite orientation, the joints damage initiation load is increased by 24.84%, the joints ultimate failure load is increased by 134.5% and the joint energy absorption is increased by 257.39%. Scanning electron microscope (SEM) observation shows that surfi-sculpts experience three damage stages.