Methodology Research On Seismic Performance Assessment Based On Damage For RC Frame Structure

It's necessary to evaluate the seismic performance of the structure by the quantitative performance index with the development of the performance-based seismic design. The damage model is an important way to quantize the structural performance objective. Therefore, in the paper, the damage models of reinforced concrete structures and the method to assess the structural seismic performance based on damage are studied on the basis of experiments.Firstly, the mechanics experiments of the steel and concrete and the pseudo-static tests of three reinforced concrete columns designed based on the current specifications are conducted. The damage process,the failure forms,the phenomena and the behaviors such as the horizontal force and the top displacement are recorded in detail.Then the test results of the reinforced concrete columns like the force-displacement curves and skeleton curves are summarized and the seismic performance of the columns is analyzed in term of the stiffness degradation, energy dissipation and ductility.Secondly, according to the test results in the paper and the one conducted by Kunnath et al, several typical component damage models based on the deformation, degradation, energy, low-cycle fatigue performance and the combination between them are selected for assessing the specimens.The suitability of the damage models are investigated. Then the effectiveness and suitability of a damage model based on material proposed by YeongAe Heo is verified via the numerical simulation results in OpenSees. The threshold of the damage index on different performance levels is obtained.Finally, the calculation of the structural damage index is implemented based on the material level and component level respectively by the reasonable weighting methods.Then the structural damage indexes are selected for the seismic demand parameters respectively.The fragility analysis based on the incremental dynamic analysis of a reinforced concrete frame is conducted considering the randomness of earthquake. The feasibility of the method to evaluate the structural seismic performance in term of the damage index is researched compared to the results based on the maximum inter-storey drift angle.