An Analytical Study on Debonding of Circular Single-Lap Patch Repairs Subjected to Axisymmetric Load

Abstract

Present paper is an analytical study on a patch repair problem. An exact solution based on a simplified plate model is obtained for single-patch-repaired circular plates with axisymmetric debondings between the patch and the base plate subjected to a uniform radial displacement, where significant bending deformation occurs owing to asymmetric configuration of the repaired plate. The debondings locate both at the outside edge of the patch and at the edge of the hole. The theoretical solution agreed well with a finite element solution. The basic mechanism of debonding problem of two dimensional patch repaired plate is discussed through the present theoretical solution and the finite element solutions. The nonlinear finite element results show that nonlinear effect is significant, while the nonlinear solution finally approaches the linear solution obtained by neglecting bending deformation. The linear solutions of energy release rate of the debonding crack with and without considering bending effect gives an upper and a lower limit. The linear exact solution neglecting bending deformation is applicable as a rough estimate at an early design stage since not only the solution gives upper limit but also the effect of the bending deformation on energy release rate of debonding crack decays quickly with the increase of the applied inplane displacement.