平面偏心结构的三维能力谱方法

A three dimensional capacity spectrum method for plan-asymmetric structures

基于单自由度模型的性态评估方法,无法考虑偏心结构平扭耦联效应且不便于考虑双向地震动输入,存在很大的局限性。本文在对水平偏心结构模态分析的基础上,利用OpenSees构建等效三自由度模型(ETDOF),将该模型用于双向地震动作用下偏心结构平扭耦联简化计算和性态评估。在对ETDOF模型进行振动特性分析的基础上,基于等位移原理,简化了计算过程,提出了偏心结构双向地震动作用下的三维能力谱方法。通过一个偏心钢框架结构算例验证了三维能力谱法的正确性。结果表明,本文方法对求解平面偏心结构的非弹性性态反应具有精度可靠、求解效率高的特点。

At present,the simplified methods for evaluating the structural performance are mostly based on the single degree of freedom system（SDOF）,which is not adequate for the asymmetric structures considering the spatial coupled effects and the multi-dimensional ground motions.Considering the plan-asymmetric and coupled characteristics of structures,a modal equivalent triple-degrees of freedom（ETDOF） system is established.Then a three dimensional capacity spectrum method（3D-CSM） is developed based on the equivalent displacement rule.In order to verify the method,an asymmetric steel frame structure is applied with nonlinear time history analysis and 3D-CSM.The results show that the 3D-CSM is reliable and effective for evaluating the seismic response of plan-asymmetric structures.