Structural Behaviour of CFRP-to-Steel Bonded Joints

The behaviour of the bonded joints between carbon-fiber-reinforced polymer (CFRP) composite strips and steel plates has been analyzed in this paper. For a better understanding of the structural response, single lap joints (SLJs) have been used, being loaded in axial tension. First, the behaviour has been investigated experimentally, by preparing 34 specimens with various types of composite strips, types of adhesvies and bonding thicknesses. Based on the results of the experimental program, the failure mechanisms were classified and the load-displacement curves were plotted. The structural response has also been studied by analyzing the strain distribution along the bond length at different load stages and by plotting the shear stress-displacement (slip) curves and the stress-strain distributions in the CFRP strips. For a better validation of the experimental results, numerical simulations have been done, based on a 3D finite element method (FEM) analysis. The results were considered consistent, being in good agreement with the experimental ones.