Fiber modelling approach for seismic analysis of flexure-controlled rc columns with ribbed bars calibrated on unidirectional experimental tests

In this paper, a fiber-section model for the seismic analysis of ductile reinforced concrete columns with ribbed bars is proposed. The model is based on the simulation of the results of uniaxial-bending experimental tests and is built by using OpenSees software. Material models are proposed to replicate the response of cover concrete, of core concrete, and of steel rebars. A modelling strategy already proposed in the literature is incorporated in the proposed model to account for strain penetration effects. Correction coefficients are calibrated to account for the additional confinement provided to the end sections of structural members by other structural members, such as foundation elements. Literature formulations are applied to account for the fracture in tension of longitudinal rebars after buckling in compression. The proposed model can be adopted for the seismic nonlinear static and dynamic analysis of reinforced concrete structures.