A model for carbon and stainless steel reinforcing bars including inelastic buckling for evaluation of capacity of existing structures

Proper steel model for reinforcing bar incorporating inelastic buckling is essential for precise seismic analysis of reinforced concrete structures. Steel model without considering inelastic buckling will obviously overestimate the corresponding stress if the rebar is under cyclic loading and the inelastic buckling emerges in compressive loading. In this paper, a modified version of the Monti-Nuti steel model that includes the inelastic buckling for reinforcing bar is proposed. This modified model considers the effect of the yielding stress on the critical slenderness and the behavioral anisotropy in tension and compression of some type of stainless steel rebars. A parameter identification is carried out to calibrate the main parameters of the modified model. The identified parameters are robust. The effectiveness of the modified model is verified comparing the numerical stress-strain curves of carbon steel and stainless steel rebar with the experimental ones