Identification and verification of seismic demand from different hysteretic models

The goal of this paper is to develop a modified Bouc-Wen hysteretic model from cyclic loading test data for reinforced columns, including the behavior of stiffness degradation, strength deterioration, pinching and softening effects of RC members. Seismic demands on this inelastic single-degree-of-freedom system when subjected to both near-fault ground motion and far-field ground motion excitations were examined. The cyclic loading test of reinforced concrete columns was experimentally observed and a system identification computer program was developed to solve each control parameter of the hysteretic model. A least-squared method for identifying parameters of the model is proposed in this paper. The hysteretic constitutive law produces a smoothly varying hysteresis such as the control-parameters for strength deterioration, stiffness degradation, pinching and softening effects. Two implementations of (1) flexure damage and (2) shear damage were conducted to provide better understanding of hysteretic behavior of RC structural members. A pseudo-dynamic experiment was also developed to verify the model paxameters. Based on the developed hysteretic model, the seismic demand of this inelastic model was investigated by using both near-fault ground motion data and fax-field ground motion data as input motion. An R-mu-T inelastic response spectrum from different hysteretic models was generated.