基于多元增量动力分析(MIDA)方法的RC核心筒结构地震易损性分析

Seismic fragility analysis for RC core walls structure based on MIDA method

RC核心筒结构在水平双向地震荷载作用下,结构地震响应的耦合作用会严重削弱筒体的变形能力和延性性能,加剧筒体结构破坏程度。引入地震动入射角来模拟结构可能遭遇到的更为客观、实际的水平双向地震激励,基于传统IDA方法,采用拉丁超立方体网络抽样法考虑地震动强度及地震动入射角对结构的共同影响,提出了多元增量动力时程分析(MIDA)方法。基于MIDA方法,利用有限元分析软件Perform-3D对20层RC核心筒结构进行多元增量动力时程分析,获取了能反映结构抗震性能的MIDA曲线,并基于性能定义出结构的四个极限性态点,进而获得结构的地震易损性曲线,对结构的易损性能进行了分析和评估。

Under bi-directional horizontal seismic load,the coupled seismic response of structure seriously weakens the cylinder deformation capacity and the structural ductility performance and thus,intensifies the structure damage.The seismic incidence angle was introduced to simulate more objectively and effectivly the horizontal seismic excitation acting on the structure.Based on the traditional increamental dynamic analysis （IDA）method,using the Latin hypercube sampling method to consider the common influences of seismic intensity and seismic incidence angle on the structure,a method by the name of Multi-component Incremental Dynamic Analysis （MIDA）method was introduced.Based on the MIDA method,a dynamic time history analysis was carried out on the reinforced concrete core walls by using the finite element analysis software Perform-3D.The MIDA curves were obtained to reflect the structural seismic performance.Four limit state points of structure were defined according to the performance,Corresponding seismic fragility curves of reinforced concrete core walls were obtained,and the vulnerability performance of the structure was analyzed and evaluated.