双向地震激励下基于二维屈服面模型的残余位移谱研究  

Residual displacement spectrum of a structural system based on a two-dimensional yield surface plasticity model subjected to bi-directional earthquake excitations

作　　者：刘巴黎 胡进军[1,2] 谢礼立[1,2] LIU Bali;HU Jinjun;XIE Lili(Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Engineering and Engineering Vibration,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所,哈尔滨150080 [2]中国地震局地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《振动与冲击》2021年第14期40-46,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目(U1939210)。

摘　　要：为了研究地震动的多维性和结构响应的空间耦合性对结构残余位移需求的影响,建立了恢复力特性符合二维屈服面模型的单质点双自由度体系(SMDDOF),提出双向地震激励下的等强度残余位移谱模型,对比分析了单向和双向地震激励下单自由度(SDOF)体系的残余位移谱。以不同场地类别的140组地震动记录为双向激励,建立统计平均的等强度残余位移谱,分析场地条件和两主轴方向刚度比对双向地震激励下单自由度体系残余位移谱的影响。结果表明:通过单自由度体系单向地震动输入建立的残余位移谱可能会低估结构残余位移需求;中长周期范围内,双向地震激励下的残余位移比谱值随刚度比的增大而增大;恢复力耦合效应对结构残余位移响应的影响取决于两主轴方向损伤的相互制约,其中一个主轴方向刚度的削弱会增大该主轴方向的残余位移需求,而另一主轴方向的残余位移需求则会有所减小。Due to the multi-dimensionality of earthquake excitations and spatial coupling of residual displacement responses,the residual displacement demand assessment of a structure subjected to single-directional earthquake excitation is usually not accurate enough.In the study,a single-mass dual-degree of freedom(SMDDOF)system under bi-directional earthquake excitations was concerned.A spectral model of residual displacements of the SMDDOF system with constant-strength performance subjected to bi-directional earthquake excitations was proposed.The residual displacement spectra of single degree of freedom(SDOF)systems subjected to single-directional earthquake excitations and SMDDOF systems under bi-directional earthquake excitations were compared and analyzed.140 sets of earthquake records in different site condition were used as the excitations,and the statistical average residual displacement spectrum of the SMDDOF system with constant-strength performance was established.The results were statistically organized to evaluate the effect of the site condition and stiffness ratio.It is concluded that,in some instances,the residual displacement demands of the structure are found to be underestimated when the SDOF system is adopted.In the medium-long period region,the values of residual displacements of the SMDDOF system subjected to bi-directional earthquake excitations increase with the increase of the stiffness ratio.The influences of the coupling effect of restoring force on the residual displacement response of the structure depend on the mutual competition of the damage performances along two principal axial directions of the SMDDOF system.The weakening of the stiffness in one principal axial direction will increase the residual displacement demand in that principal axial,while the residual displacement demand in the other principal axial will decrease.

关 键 词：双向地震激励 残余位移 刚度比 场地类别 强度折减系数 

分 类 号：P315.9[天文地球—地震学]