基础隔震结构的运动方程与阻尼矩阵在动力响应分析中的适用性研究  

Applicability of equation of motion and damping matrix of base-isolated structure in dynamic response analysis

作　　者：李世渊 谭平[1,2,3] 马海涛 LI Shiyuan;TAN Ping;MA Haitao(School of Civil Engineering,Guangzhou University,Guangzhou 511442,China;MOE Key Lab of Earthquake Resistance,Earthquake Mitigation and Structural Safety,Guangzhou University,Guangzhou 510405,China;Guangdong Provincial Key Lab of Earthquake Engineering and Applied Technology,Guangzhou University,Guangzhou 510405,China)

机构地区：[1]广州大学土木工程学院,广州511442 [2]广州大学工程抗震减震与结构安全重点实验室,广州510405 [3]广州大学广东省地震工程与应用技术重点实验室,广州510405

出　　处：《振动与冲击》2023年第1期198-206,248,共10页Journal of Vibration and Shock

基　　金：国家重点研发计划(2019YFE0112500);国家自然科学基金(51978185);教育部创新团队研究发展计划(IRT13057)。

摘　　要：结构阻尼模型和运动方程是影响结构抗震动力分析精度的关键因素。由于基础隔震结构地震响应具有显著的特殊性,因此普通非隔震结构地震响应算法未必适用。基于这一认识,重点研究基础隔震结构动力分析方法中采用的各种模型,考虑基于不同地震动输入的结构阻尼模型和运动方程。研究发现,采用现有常规方法构造隔震结构阻尼模型时,上部结构会随着隔震支座发生刚体位移时产生阻尼力,这将可能导致计算精度的显著降低。针对这一问题,提出了确定基础隔震结构阻尼矩阵的一般方法,给出了基于上部结构阻尼矩阵和隔震层阻尼常数的通用表达式。采用隔震结构剪切型模型,给出了结构矩阵的解析表达式,并以此为基础进行了算例验证。研究结果表明,目前常用的隔震结构阻尼模型可能会高估结构的阻尼作用,从而低估结构响应;采用位移输入模型会高估隔震层相对位移、低估上部结构响应,当隔震层等效阻尼比达到0.3时,相对偏差可达到34.6%和-31.1%,而采用位移-速度输入模型可得到与加速度输入模型一致的分析结果,故应采用位移-速度输入模型代替传统的位移输入模型。Structural damping model and equations of motion are key factors affecting accuracy of structural aseismic dynamic analysis.Due to seismic response of base isolated structure havingsignificant particularity,common seismic response algorithm of non-isolated structures may not be applicable.Here,based on this understanding,various models used in dynamic analysis of base isolated structure were mainly studied considering structural damping models and equations of motion based on different ground motion inputs.It was shown that when existing conventional methods are used to construct damping model of isolated structure,superstructure can generate damping force with isolated support having rigid body displacement to possibly cause a significant reduction of calculation accuracy.To solve this problem,a general method to determine damping matrix of base isolated structure was proposed,and a general expression based on damping matrix of superstructure and damping constant of isolation layer was deduced.Adopting the shear model of isolated structure,the analytical expression of structure matrix was given and verified with examples.The results showedthat the current commonly used damping models of isolated structure may overestimate damping action of structure and thus underestimate structural response;using the displacement input model can overestimate relative displacement of isolation layer and underestimate response of superstructure,when equivalent damping ratio of isolation layer reaches 0.3,relative deviation can reach 34.6%and-31.1%,while using the displacement-velocity input model can obtain the analysis results consistent to those obtained using the acceleration input model,so the traditional displacement input model should be replaced by the displacement-velocity input model.

关 键 词：基础隔震 运动方程 阻尼矩阵 位移输入模型 地震动输入模型 

分 类 号：TU311.3[建筑科学—结构工程]