New optimized numerical solution of interfacial stresses in steel strengthened structures with CFRP

Abstract

Fiber-reinforced polymers (FRPs) are widely used in many structural applications, such as rehabilitating and reinforcing different structures that are subjected to risks of external damage, because of their excellent material properties. However, this technique leads to a delami-nation problem, which is a failure mode that occurs between the FRP patch and the retrofitted structure and is caused by the interfacial stress concentration in the adhesive layer, thereby reducing the effectiveness of this reinforcement technique. Thus, the objective of this research is to investigate the taper effect of multilayer FRP patch on the reduction of the interfacial stresses, including fiber orientation and shear-lag effect, while thermo-mechanical loads are applied. An analytical model is developed to predict the interfacial stresses in the adhe-sively patched structures with FRP. A numerical simulation using finite element method is also employed to validate the results from the analytical analysis. Finally, a parametric study is carried out in order to determine the influence of each parameter and to determine the optimal configurations.