Simple Phenomenological Model for Reinforcing Steel under Arbitrary Load

A new formulation for a robust, yet simple, uniaxial material model for reinforcing steel subjected to arbitrary loading is presented. The model provides steel stress as an explicit function of the total steel strain and can account for nonlinear monotonic envelope curves, i.e., with a yield plateau and nonlinear strain hardening, degradation of the yield limit as a function of the plastic strain history (Bauschinger effect) and strain hardening phenomena. Suggested model input parameters for typical reinforcing steels used in the United States are provided and the characteristic behavior of the model is illustrated through comparison with experimental results.