Stress analysis of adhesive in a cracked steel plate repaired with CFRP

To repair a cracked steel-plate with carbon fiber reinforced polymer (CFRR) is an effective and simple method to strengthen a cracked region in a steel structure, which can improve security and extend steel structure's lifetime. As the repaired structure is subjected to tension loads, initial damage usually occurs in the adhesive. In this paper, the stress distributions of adhesive in a cracked steel plate repaired with CFRP were obtained based on a theoretical method and the finite element method (FEM) with different crack lengths. The maximum shear stress and peel stress in the adhesive were obtained from products of stress ratios and stresses for the case of a through-wall crack. As stress ratios could be approximated as a curve independent of material combinations, and stresses for a repaired steel plate with a through crack have explicit expressions, we could simply predict adhesive failure or the maximum load using quadratic stress criteria.