Hysteretic Model of Ordinary and High-Strength Reinforcing Steel

Abstract

The hysteretic behavior of reinforced concrete structures depends to a large extent on the hysteretic behavior of reinforcing steel. An accurate and computationally efficient numerical model of reinforcing steel is, thus, very important in the analysis and evaluation of these structures under cyclic loads, including earthquake loads. A new macroscopic hysteretic model of the short-term cyclic behavior or ordinary and high-strength reinforcing steel is presented. The model is based on a uniaxial stress-strain relation that is expressed in terms of natural stresses and strains, so that a single envelope curve governs the monotonic behavior in tension and compression. The hysteretic model accounts for the degradation of strength properties with accumulation of plastic strains. The material parameters of the model are calibrated with monotonic tests of coupon specimens, while strength degradation relations are derived from cyclic test data. Correlation studies of the model with available experimental data for ordinary and high-strength reinforcing steel demonstrate the ability of the model to simulate the hysteretic behavior of all types of reinforcing steel over a wide range of strain variations.