Finite element modelling of curved soffit reinforced concrete beams strengthened with fibre reinforced polymer

In this study, two-dimensional nonlinear finite element (FE) analysis was carried out to model simply supported curved-soffit reinforced concrete (RC) beams strengthened with CFRP sheets. Five models of simply-supported RC (curved and flat) soffit beams were loaded monotonically with one incremental concentrated load up to failure. The beams were simulated to obtain the load versus mid-span deflection, failure load, and failure mode, in order to understand the influence of concavity on the performance of this type of structural member. Five experimental beams were considered in this study. All models had an identical cross-sectional area and effective span similar to those of the experimental beams. The curvature of the curved-soffit beams adopted was 20 mm per metre. The results show that curvature of 20 mm per metre reduces the efficiency of FRP strengthening by 17.8%, and beams experience premature CFRP de-bonding due to the high concentration of tensile stresses generated by the induced curvature. Interfacial cracks followed by de-bonding are the dominant failure mode. The peak load, crack patterns and load-displacement curves of the experimental tests were simulated accurately using a nonlinear FE prediction models.