Class of Masing Models for Plastic Hysteresis in Structures

Abstract

A nonlinear structural model for the planar seismic response of steel structures is based on a class of models for the interstory force-deformation relationship which involves only two simple hysteresis rules. A model in the class is chosen by specifying a virgin loading curve, then the complete hysteretic behavior for arbitrary loading is determined. These models are an extension of Masing's models for steady-state cyclic behavior. The two simple rules also describe the behavior of the Distributed-Element Models consisting of a finite or infinite set of ideal elasto-plastic elements connected in parallel. This connection provides a physical basis for the models. Using response data from a full-scale six-story steel structure tested pseudo-dynamically in Japan under earthquake excitation, a system identification method is applied to a subclass of these models. The identified model gives good agreement with the observed inelastic behavior of the test structure, suggesting that these models may be useful for the planar hysteretic behavior of structures, particularly since the model parameters can be estimated during design from material properties and structural drawings.