Numerical and experimental analysis of Al/GFRP joint for optimization of adhesive bonding strength using response surface method by considering surface patterning of the joints

Nowadays, adhesive bonding of metals and composites is widely used in the aerospace, automotive and military industries. In the present research, the finite element analysis (FEA) and response surface method (RSM) are used to optimize adhesive bonding strength between aluminum (Al) and glass fiber reinforced polymer (GFRP). For this purpose, the influence of the parameters of joint type, groove shape, groove number, and groove angle was investigated on the bonding strength. The joint type includes Al/Al, Al/GFRP and GFRP/GFRP, the groove shape includes V-shape, square and concave, the groove number includes 1, 3 and 5 grooves, and the groove angle includes 0, 45 and 90°. In order to model the crack growth in the simulation of adhesive bonding, the cohesive zone model was applied. Finally, the optimal sample is fabricated to examine its strength in temperature-humidity environmental conditions. The results of simulation and optimization indicated that the bonding strength improved in Al/Al mode with one square groove at 0° groove angle. The stress-strain diagram obtained from the simulation and optimization results was in good agreement with the sample made under optimal conditions. Moreover, the tensile strength of the optimal sample at temperature-humidity conditions was higher than the tensile force of the sample without groove.