多层钢框架结构的区域震害模拟多自由度模型∗

传统的易损性分析方法难以满足城市区域震害预测的需求。基于非线性多自由度层模型和动力时程分析的城市抗震弹塑性分析方法近年来得到快速发展。为了进一步丰富区域震害模拟的可模拟结构类型,基于城市抗震弹塑性分析方法的流程框架,建立了多层钢框架结构的多自由度剪切模型。通过统计规范中的公式参数和文献中的钢框架推覆结果,对模型的周期、阻尼比、骨架线参数和滞回曲线参数进行了标定,并根据文献和美国 HAZUS 报告给出了多层钢框架结构的损伤判别准则。最后,分别使用文献中的试验结果和文献中设计实例的推覆分析结果对模型进行了验证。结果表明:(1)建立了多层钢框架结构的多自由度剪切模型并进行了参数标定,为区域震害模拟提供了可用模型;(2)对多层钢框架结构的损伤判别准则进行了标定,可以根据区域震害模拟结果评价其破坏状态;(3)在考虑骨架线参数不确定性的情况下,模型精度满足区域震害模拟的要求。

A Multi-Degree-of-Freedom Model for Regional Seismic Damage Simulation of Multi-Story Steel Frame Structures

Urban seismic damage is difficult to predict using traditional vulnerability analysis method.The cityscape nonlinear time-history analysis of urban buildings based on nonlinear multi-degree-offreedom(MDOF)models and the time-history analysis have been developed rapidly in recent years.In order to include more structural types in the simulation using the regional seismic damage simula?tion method,the MDOF shear model of multi-story steel frame structures is established based on thesimulation framework of the cityscape nonlinear time-history analysis. In this work,formulas and pa?rameters in the design code are investigated,and the pushover results of steel frames in literatures arecollected. Subsequently,the period,damping ratio,backbone curve parameters and hysteretic curveparameters are determined. Furthermore,the damage criteria of multi-story steel frame structures are?determined according to literatures and the HAZUS report. Finally,the model is validated through ex?periment results in literatures and the pushover analysis results of the designs in literatures,respective?ly. The main conclusions are as follows:(1)The MDOF shear model of multi-story steel frame struc?tures is established and the parameters are determined,which provides a useful model for regional seis?mic damage simulation of steel frame structures.(2)The damage criteria of multi-story steel framestructures are determined,and the damage state can be evaluated according to the simulation resultssubsequently.(3)The validation result shows that the model can satisfy the accuracy demand of re?gional seismic damage simulation considering the uncertainty of backbone curve parameters.