Analysis on the parameters of adhesively bonding patch repairing cracked sandwich face panel

The parameters of adhesively bonding patch, which include patch materials, patch size, patch thickness, have been analyzed on the stress concentration factor and the stress intensity factor (SIF) thanks to the 3D finite element method (FEM) in the paper. The adhesive shear modulus and thickness are studied in this paper as well. The aluminum sandwich face panel is analyzed and the results show that the Boron/Epoxy composite patch reduces more stress concentration factor and SIF comparing with the other patches. The stress concentration factor reaches the minimum when the fiber orientates the tension direction. Meanwhile, the stress concentration in the patch and the adhesive reach the maximum. The stress concentration factor in the aluminum face sheet decreases with the increasing patch thickness. But the effect of the patch thickness weakens when the patch thickness is larger than the face panel. The impact of the adhesive thickness on the stress concentration of the face panel reduces with the increasing adhesive shear modulus. The stress concentration factor increases when the adhesive thickness increases. The results are useful to design the bonded composite patch repair.