一种基于子结构界面动刚度的模态综合法  

A modal synthesis method based upon dynamic stiffness on interface

作　　者：诸赟[1] 张美艳[1] 唐国安[1] 

机构地区：[1]复旦大学力学与工程科学系,上海200433

出　　处：《振动工程学报》2015年第3期345-351,共7页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(11202052)

摘　　要：针对传统模态综合法中由于高阶截断模态带来的计算误差问题,将子结构界面动刚度展开成频率的泰勒级数,表示为子结构的固定界面主模态。利用位移协调和力平衡条件对子结构界面动刚度进行模态综合,保留了截断模态高阶项的部分贡献,发展了一种新的模态综合方法。推导过程不必引入质量矩阵为对角块的假设,比现有改进方法更具普适性。数值算例的结果表明在相同自由度的前提下,该方法能获得更高的模态综合精度。A new modal synthesis method is proposed in this paper for reducing errors caused by higher order modal truncations. Through series expansion, the dynamic stiffness on substructure interface is represented by the normal mode of the fixed-interface substructure. In addition, geometrical compatibility and force equilibrium on substructure interface are employed in the modal synthesis of the dynamic stiffness. Thus, a new methodology of substructure synthesis is obtained. The higher order force equilibrium on the substructure interface is employed to achieve the model reduction. Compared to Craig-Bampton method, this method keeps the contribution of the higher order terms of the truncated modes so that it can improve the accuracy of the modal synthesis. The deduction doesn＇t introduce the assumption of the diagonal mass matrix which makes the method more general. The numerical result is given to show the effectiveness of the method.

关 键 词：动态子结构 模态综合法 动刚度 

分 类 号：O326[理学—一般力学与力学基础] V214.1[理学—力学]