Numerical analysis of fiber composite-steel plate upgraded beam–column sub-assemblages under cyclic loading

In the present study, exterior beam–column sub-assemblage from a regular RC building has been considered. Extremely poor gravity load designed (GLD) beam–column sub-assemblage was upgraded by combinely using FRP and steel plate. Three different upgradation schemes have been proposed. Nonlinear finite element (FE) program has been employed for analysing both existing and upgraded sub-assemblages under cyclic loading. Concrete parts of the FE models were modelled using quadratic brick – and steel plates were modelled using tetrahedral – solid elements. All the FRPs were modelled as 9-noded iso-parametric multi-layered shell elements with embedded unidirectional reinforcement to represent the anisotropic material property. Contact elements and bond properties were suitably incorporated. It has been found out that the results obtained from the numerical analysis are well corroborated with those of experimental results. Further, a detailed parametric study has been carried out on type, extent and amount of flexural strengthening, and number of wrapping to identify the scopes of improvement on the proposed upgradation schemes.