基于能量范数的模态密集型系统的模态截断  

MODAL ABSCISSION OF MODAL CONCENTRATION SYSTEM BASED ON ENERGY NORM

作　　者：宋修广 钟原 刘西利 

机构地区：[1]山东大学土建与水利学院岩土与结构工程研究中心 [2]滨洲市公路管理局 [3]潍坊市公路局 250061.山东省济南市 [4]256617.山东省滨洲市 [5]250002.山东省潍坊市

出　　处：《山东大学学报（工学版）》2002年第4期321-324,共4页Journal of Shandong University（Engineering Science）

摘　　要：在求解线性振动系统响应的模态叠加法中，一般作模态截断的根据是系统响应级数的收敛性，但对于模态密集型系统，由于固有频率密集，造成响应级数收敛较慢，需使用大量的主模态才能其收敛。因此本文就模态密集型系统作模态截断时系统主模态数取多少，采用了能量范数形式的判断指标；并以某拱坝的动力响应为算例，判断指标与所取主模态数的关系表明：小湾拱坝的动力分析需取10阶左右的主模态进行叠加。Making use of modal summation method on dynamic response calculation of the linear oscillation system,modal abscission was based on convergence of the response series.For modal concentration system,the response series may be converged by use of large principal modes due to natural frequency concentration .In order to make sure how many principal modes must be fetched on modal abscission of modal concentration system,judging indicator which form is energy norm is given.Dynamic response analysis of a arch dam is given for illustration.The relations between judging indicator and fetched number of principal modes can suggest that 10 or more principal modes must be fetched on dynamic analysis of the arch dam.

关 键 词：能量范数 模态截断 模态分析 拱坝 固有频率 模态密集型系统 模态叠加法 线性振动系统 

分 类 号：TV642.4[水利工程—水利水电工程] TV31