Bending and vibration characteristics of damaged RC slabs strengthened with externally bonded CFRP sheets

This paper deals with the bending and vibration analyses of damaged moderately thick slabs strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) sheets. In the analytical formulation, the two adherends and the adhesive layer are all modeled as shear deformable plates using the first order shear deformation plate theory. The anisotropic damage model is adopted to describe the damage extent of the reinforced concrete (RC) slabs. The total potential energy of a locally damaged slab strengthened with an externally bonded sheet is derived. Trigonometric series are used to present the shape functions of strengthened slabs and Rayleigh–Ritz method is employed to determine the deflections and stresses in the case of bending analysis, and natural frequencies in the case of linear eigenvalue problems of vibration. Several test problems are examined to demonstrate the accuracy and effectiveness of the proposed method. Numerical results are presented that relate to the performance of damaged RC slabs bonded with CFRP sheets, in which a damaged RC slab strengthened by a thin steel sheet is treated as a comparator. The effects of damage extent and the effects of the bonded sheet on the bending and vibration characteristics of damaged RC slabs are also studied.