Effect of stacking sequence of the bonded composite patch on repair performance

Abstract

In this study, the three-dimens ional finite element method is u sed to determine the stress intensity factor in Mode I and Mixed mode of a centered crack i n an aluminum specimen repaired by a composite patch using contour integral. Various mesh densities were used to achieve convergence of the results. The effect of adhesive j oint thickness, patch thicknes s, patch-specimen interface and layer sequence on the SIF was highlighted. The results obtained show that the patch-specimen contact surface is the best indicator of the deceleration of crack propagation, and hence o f SIF reduction. Thus, the reduction in rigidity of the patch especially at adhesive layer-patch interface, allo ws the lowering of shear and normal stresses in the adhesive joint. The choice o f the orientation of the adhesi ve layer-patch contact is important in the evolution of the shear and peel stresses. The patch will be mor e beneficial and effective while using the cross-layer on the contact surface.