基于拟力法的钢框架易损性分析

Analysis of Steel Frame Vulnerability Based on Force Analogy Method

采用拟力法最大的优点在于求解结构动力非线性问题的时效性。基于拟力法的基本假定，框架结构刚度保持不变且塑性变形仅发生在构件端部，用弯曲塑性铰描述塑性变形，相比有限元方法，具有存储空间小、计算速度快和计算精度高等优势。本文将拟力法应用到钢框架的抗震性能评估中，以结构最大层间位移角为参考指标定义结构4种破坏状态，依据选拔原则选取16条地震波，采用IDA方法对-6层钢框架结构进行易损性分析，绘制其易损性曲线。对比有限元方法计算分析，拟力法在计算耗时上显示出巨大的优势，适用于框架结构地震灾害风险分析与灾后快速评估。

The biggest advantage of the pseudo force method is its timeliness for solving structural dynamic nonlinear problem. Based on the basic assumption of the pseudo force method, frame stiffness keeps unchanged and plastic deformation occurs only at the bottoms, compared with finite element method, using curved plastic hinge to describe the plastic deformation, a sma｜i storage space, fast calculation speed and high precision computational are its advantages. In this paper, the pseudo force method is applied to the evaluation of seismic performance of steel frame structure, four kinds of damage state is defined with the maximum inter storey displacement angle as a refer- ence index, 16 earthquake waves are selected according to the selection principle, practice vulnerability analysis for a 6 - storys steel frame structure using IDA method and render the fragility curve. Compared with calculation analysis of finite element method, the pseudo force method shows great advantage in computing time, it is suitable for frame structure in earthquake disaster risk analysis and post disaster rapid assessment.