ABSTRACT
Application of high tensile steel in various structural forms such as rolled or fabricated sections is currently increasing due its mechanical and economic advantages. Experimental investigations show the distinct plastic behavior of high tensile steel with grades greater than 700 MPa damaged under reversed tension-compression loading scenarios compared to the hardening performance of lower grades of steel. This paper investigates a combined nonlinear plastic model to predict the stress-strain equations of grades 800 and 1200 steel extracted from circular tubes under very low cycle structural damage. In the numerical modelling phase, relevant parameters are calibrated and model is verified against hysteretic experimental results. The numerical results provide a simulation tool for structures consisting of high tensile steel tubes under seismic loads.
