模态综合法精度分析

Accuracy Analysis of Modal Synthesis Method

模态综合法是研究振动问题的常用方法。本文以均匀直角梁在它本身平面内的弯曲振动问题为例,运用模态综合法,选取不同主振型,分别计算它的平面弯曲振动的前两阶固有频率,比较不同主振型下所得出的近似频率的精度。同时,将模态综合法两种不同振型下的计算结果与有限元法计算结果相比较,通过近似频率的精度比较,来分析不同振型下模态综合法的计算精度。

Modal synthesis method is a common way to study vibration problem. Based on uniform rectangular beam in plane bending vibration problem of itself, this article will use the modal synthesis method and select different main vibration mode to calculate separately the beam＇s first two order natural fre- quency of plane bending vibration and compare the approximate frequency. At the same time, under the two different modes of the calculation results, the modal synthesis method are com- pared with the the results calculated by finite element method, by comparing the accuracy of the approximate frequency, it will analyze the calculation precision of modal synthesis method, un- der different vibration mode.