Development of Hysteretic Model with Dynamic Effect and Deterioration for Seismic-Performance Analysis of Reinforced Concrete Structures

In this paper, an innovative approach is developed to consider the impacts of dynamic effect and deterioration on the seismic performance analysis of reinforced concrete (RC) frame structures. Firstly, based on the dynamic loading test database of RC column specimens, the predicted models of dynamic modified coefficients (DMCs) are constructed to take into account the impacts of dynamic effect on the yielding and ultimate strength, effective stiffness, and ductility coefficient of RC columns. Secondly, a damage index-based hysteretic model is proposed to reflect both cyclic and in-cycle performance degradation of RC columns under cyclic dynamic loading. Finally, by employing the DMCs into the hysteretic model of RC members, the influences of dynamic effect and deterioration on the seismic behaviors of a RC frame structural model, which is a prototype structure suffering from severe seismic damage during the Yushu earthquake in China, are comprehensively investigated. The superiority of the proposed approach over the traditional method lies in that both the beneficial and adverse impacts of dynamic effect can be considered. Moreover, the effectiveness of the developed models is verified with the dynamic loading experimental observations. By comparing the numerical results of seismic responses between the rate-independent and rate-dependent models, it is found that the dynamic effect can exert dual influences on the structural seismic performance. For the frame models subjected to earthquakes with small intensities, the displacement response and damage degree can be reduced due to the strength and stiffness enhancement of structural members. As for the frame models under large intensity excitations, the structural damage is aggravated and the failure mechanism may be affected owing to the decreased ductility and intensified deterioration of RC members. To provide a more reliable seismic-performance assessment of RC structures, it is suggested that the combined influences of dynamic effect and deterioration should be given an adequate consideration in the further research works. (C) 2020 American Society of Civil Engineers.