强震下单自由度体系残余位移离散性研究

Study on the dispersion of residual displacement of SDOF system under strong earthquake

针对双线性单自由度体系,定义了4种强震下残余位移的量化指标,然后选取100条地震动,通过弹塑性动力时程分析,研究了结构基本周期、屈服后刚度系数、强度折减系数对残余位移离散性的影响,最后对残余位移和最大位移之间的相关性进行了研究。结果表明:残余位移、残余位移与屈服位移之比的离散性最大,残余位移与最大位移之比的离散性最小;残余位移的离散性受结构基本周期、屈服后刚度系数的影响较大,且随着结构基本周期的增大而变大,受强度折减系数的影响较小;残余位移和最大位移之间存在较强的相关性,且受结构基本周期和强度折减系数的影响较小,受屈服后刚度系数的影响较大。

Four quantitative indexes for residual displacement under strong earthquake are defined for the bilinear SDOF( single degree of freedom) system,and the influences of structure period,post-yielding stiffness coefficient and strength reduction factor on the dispersion of residual displacement are studied by way of elastic-plastic time history analysis using 100 earthquake records. Finally,the correlation between the residual displacement and maximum displacement is also investigated. The results indicate that the residual displacement or the ratio between the residual displacement and yield displacement has the largest dispersion,while the discreteness of the ratio between the residual displacement and maximum displacement is the smallest. The structure period or post-yielding stiffness coefficient has large impact on the dispersion of the residual displacement and the dispersion is larger with the increase of the structure period,while the strength reduction factor has little effect. The residual displacement has strong correlation with the maximum displacement,which is highly affected by the post-yielding stiffness coefficient while less related to the structure period or strength reduction factor.