摘要
基于模态展开法、幂级数展开原理和移频技术，提出了一种计算频响函数的模态加速方法．当外激励的频率处于系统的低频区时，运用该方法可对系统的中、高阶模态实施截断和加速；当外激励的频率较高而处于系统的中频区时，该方法可对系统的低阶和高阶模态同时实施截断和加速，使模态展开时所需的模态数大为减少．通过对一个二维框架结构计算表明，模态加速的效果明显，通常只需计入幂级数的前几项即可使频响函数达到很高的精度．
Based on the modal superposition method, power series expansion principle and eigenvalue shifting technique, a modal acceleration method for calculating frequency response function (FRF) is derived in this paper. By using this method, the higher modes of the system can be truncated and accelerated when the excited frequencies lie in the low frequency range of the system, and the higher and the lower modes can be truncated and accelerated at the same time when the excited frequencies lie in the middle frequency range. This makes the number of the modes needed in modal superposition relatively small. The results of a two dimensional frame structure show that the modal acceleration technique is very efficient when the modal truncation is applied and the approximate FRF is of high accuracy provided several preceding items of the power series are taken into account.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
1998年第7期40-43,共4页
Journal of Shanghai Jiaotong University
关键词
频响函数
模态分析
模态加速
幂级数展开
frequency response function
modal analysis
modal acceleration
power series expansion
