黏滞阻尼器对高层钢结构地震易损性的影响

为研究黏滞阻尼器对高层钢结构地震易损性的影响,基于Open SEES有限元分析平台,建立一个25层钢框架结构以及同尺寸附着黏滞阻尼器的钢框架结构,对两个钢框架结构以地震动峰值加速度(PGA)作为地震动强度指标,以结构最大层间位移角θmax为工程需求参数,从太平洋地震工程研究中心(PEER)中选取了15条地震动记录,分别对两个结构进行增量动力分析(Incremental Dynamic Analysis,IDA),建立结构的IDA曲线簇。结合地震易损性分析,对分析结果进行对数拟合,构筑两个结构的连续易损性曲线,并进一步提出用贝塔分布函数将结果转化为地震动参数-震害指数概率密度函数的概率表达方式,可以更加直观简便地观察到黏滞阻尼器显著的减震效果。该表达方法具有直观性,研究成果可为既有结构的地震灾害风险评估等提供简明且有力的分析方法。

Effect of viscous damper on seismic vulnerability of high-rise steel structures

To study the effect of viscous damper on seismic vulnerability of high-rise steel structures,a 25-story steel frame structure with or without the viscous dampers was established based on the OpenSEES platform.The peak ground acceleration(PGA)was chosen as the ground motion intensity index.The maximum intra-story Drift Umax was used as the engineering demand parameter.15 ground motion records were selected from the Pacific Earthquake Engineering Research Center(PEER)database based on the combination of earthquake and station information.Incremental dynamic analysis(IDA)approach was used to perform structural analysis to establish the IDA curves for the two structures.Logarithmic normal distribution was used to fit the curve for seismic vulnerability analysis.In order to construct continuous vulnerability curves,beta distribution was used to convert the vulnerability analysis results into the ground motion parameter-damage index probability density functions.As shown in the results,significant damping effect of the viscous damper was observed.The direct expression of ground motion versus damage index for vulnerability can be readily applied in earthquake loss and risk assessment of engineering structures.