基于大质量法的结构零频率振型的动力特性  

Dynamic Characteristics of Structural Modes with Zero Frequency Based on Large Mass Method

作　　者：楼梦麟[1] 田仲业 LOUMenglin;TIAN Zhongye(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;SUNAC China Holdings Southeast Regional Zhedong Company,Ningbo 315121,Zhejiang,China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]融创中国东南区域集团浙东公司,浙江宁波315121

出　　处：《力学季刊》2020年第2期240-248,共9页Chinese Quarterly of Mechanics

基　　金：国家自然科学基金(91315301);科技部国家重点实验室基础研究资助项目(SLDRCE08-A-07)。

摘　　要：在介绍大质量法基本原理的基础上,根据多点输入下结构无阻尼动力反应方程,通过理论推导论证了基于大质量法所得到的结构体系零频率振型的动力特性.理论推导的结果表明:基于大质量法的结构零频率振型为该结构的拟静力模态向量的线性组合,其中组合系数为该结构零频率振型中对应于结构基底释放自由度的子向量中的各个元素.最后,通过3个简单多自由度动力体系的数值结果验证了上述结论.Based on the introduction for the principle theory of large mass method,the dynamic characteristics of structural modes with zero frequency obtained from the large mass method are verified according to the dynamic analysis equations of the structure without damping under the multiple-point excitations.The result of theoretical derivation shows that the mode with zero frequency from the large mass method is the linear combination of the pseudo-static modes of the structure,and the combination coefficients are the elements in sub-vector of this mode with zero frequency corresponding to DOFs released from the structure base.Finally,the conclusion is validated by the numerical results of three simple multiple-degree-of-freedom dynamic systems.

关 键 词：大质量法 模态分析 零频率振型 拟静力模态 线性组合 

分 类 号：TU311.3[建筑科学—结构工程]