University of Qom Civil Infrastructure Researches 2783-140X 7 1 2021 08 23 Simulating Effect of FRP Sheets on Nonlinear Behavior of Reinforced Concrete Beam- Column Connections Simulating Effect of FRP Sheets on Nonlinear Behavior of Reinforced Concrete Beam- Column Connections 131 151 1971 10.22091/cer.2021.7364.1296 FA Mahdi Nematzadeh Department of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran Sina Baharlo Department of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran Javad Shayanfar Department of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran Seyed Mohammad Reza Hasani PhD Candidate, Faculty of Civil Engineering, Babol Noshirvani University, Babol, Iran. Journal Article 2021 09 14 The vulnerability and improper seismic behavior of beam-column connections in reinforced concrete structures designed based on past codes without seismic considerations has been established through data obtained from experiments and past earthquakes. In this research, the use of fiber-reinforced polymer (FRP) sheets attached to the surface of the member for strengthening connections was investigated. Here, an analytic model was presented for simulating the nonlinear behavior of connections strengthened with FRP sheets. In this model, the nonlinear behavior of the core zone of the connections was simulated with two diagonal linear springs. The corresponding load-displacement relationship in the linear springs is a function of the principal tensile stress-shear deformation in the core zone of the connection. Therefore, based on the behavioral mechanism of the connections and using the experimental results, the principal tensile stress-shear deformation relationships for reinforced concrete connections with different restraints for the longitudinal rebars of the beam were developed. Comparing the results of the numerical model with those obtained from the experiments verified the ability of the proposed model in predicting the nonlinear behavior of connections strengthened with FRP sheets. The vulnerability and improper seismic behavior of beam-column connections in reinforced concrete structures designed based on past codes without seismic considerations has been established through data obtained from experiments and past earthquakes. In this research, the use of fiber-reinforced polymer (FRP) sheets attached to the surface of the member for strengthening connections was investigated. Here, an analytic model was presented for simulating the nonlinear behavior of connections strengthened with FRP sheets. In this model, the nonlinear behavior of the core zone of the connections was simulated with two diagonal linear springs. The corresponding load-displacement relationship in the linear springs is a function of the principal tensile stress-shear deformation in the core zone of the connection. Therefore, based on the behavioral mechanism of the connections and using the experimental results, the principal tensile stress-shear deformation relationships for reinforced concrete connections with different restraints for the longitudinal rebars of the beam were developed. Comparing the results of the numerical model with those obtained from the experiments verified the ability of the proposed model in predicting the nonlinear behavior of connections strengthened with FRP sheets. https://cer.qom.ac.ir/article_1971_e2a6f3cc1523437123525430174a18d7.pdf