基于单自由度等效线性化模型的RC结构地震易损性分析

通过有限元方法进行非线性动力时程分析获取解析的易损性曲线，计算量大且耗时。本文采用一种简化的计算方法，即基于单自由度的等效线性化模型，对钢筋混凝土框架结构进行地震易损性分析，并研究了该方法在结构高度上的适用性。通过选用5种典型的等效线性化模型对3栋不同高度的钢筋混凝土框架结构进行增量动力分析（IDA），得到了不同高度的结构在不同强度地震作用下结构的反应和易损性，并与OpenSees程序的计算结果进行对比，研究了等效线性化模型应用于RC框架结构易损性分析在高度上的适用性。分析结果表明:对于10层及以下的框架结构，基于单自由度的等效线性化模型在结构地震易损性分析中具有较好的适用性；对于更高层数的结构，由于高阶振型反应对整体结构反应的影响增大，基于单自由度等效线性化模型的易损性分析结果会出现明显的偏差。

Fragility Analysis of RC Frame Structures Based on Equivalent Linearization Method of SDOF System

Obtaining the analytical fragility curves through nonlinear dynamic time history analysis of FEA model is computationally intensive and time-consuming. In this paper, we used a simplified calculation method, namely the equivalent linearization method based on single degree of freedom, to analyze the seismic vulnerability of reinforced concrete frame structures and the applicability of this method for structures with different heights. The incremental dynamic analysis (IDA) for three reinforced concrete frame structures with different heights was carried out by using five typical equivalent linearization methods. The response and vulnerability of structures with different heights under different earthquakes were obtained. Compared with the results of OpenSees program, the applicability of the equivalent linearization method to the vulnerability analysis of RC frame structure is investigated. The result shows that for RC structures with height less than 10 stories, the equivalent linearization method based on single degree of freedom has good applicability for structural seismic vulnerability prediction. For higher structures, the influence of the high-order mode response on the overall structural response increases and the vulnerability analysis result based on the single-degree-of-freedom equivalent linearization method shows a significant deviation.