Numerical analysis of a new composite patch design effect for repairing a damaged steel structure with an inclined crack (mixed mode I+II)

Abstract

The available studies in the field of repair of damaged structures aim at reducing the high stress concentrations in the damaged area by optimizing the geometric and mechanical parameters of the composite patch. The geometric modifications are mainly performed on the repair patch based on standard geometric shapes (square, rectangle, triangle, or elliptical) intended for the repair of an aluminum structure. The present work highlights a non-standard geometric shape of the composite patch to repair a DH36 steel plate under mode I and mixed mode cracks using the finite element method (FEM). The composite patch performance regarding the damaged plate strength was validated by determining the J-integral in the plate and by evaluating the Von Mises stress in the adhesive and the principal stress in the patch to estimate the load transfer. The effect of the crack size, the patch material, and the geometric parameters of the patch were evaluated. The results of the numerical analysis show that the proposed patch shape, compared to the conventional shapes, provides an increased reduction of the J-integral in mode I and mixed mode, and that the patch ensures a good load transfer