Experimental characterization of CFRP single lap joints under tension at various loading rates

The objective of this study is to experimentally characterize the performance of four different compos-ite/composite single lap joint configurations at various loading rates. The four joint configurations are single bolted joint, simply bonded joint, single bolted hybrid joint (a single bolt is used along the lap length of a simply bonded joint) and multiple micro bolted hybrid joint (four micro-bolts are used along the lap length of a simply bonded joint). The lap joints are tested at various loading rates using tensile split-Hopkinson bar and fatigue testing machine. Experiments reveal that, for a given joint configuration, the peak load, initial stiffness, and energy absorbed generally increased with the loading rates, whereas the plateau load is relatively insensitive to the loading rates. Finite element analysis (FEA) using the commercial software Abaqus/Explicit solver for all the configurations is also performed to simulate experimental loading conditions. It has revealed that by accounting for rate dependency of adhesive one can qualitatively explain the experimental observations.