摘要
本文讨论了应用Wilson-Ritz向量法分析结构模态特性所遇到的一个基本问题——如何定义荷载分布向量,并在Rayleigh原理的基础上,介绍获取Ritz向量的迭代计算公式。算例表明,应用本文建议的方法能有效地提高大型结构振动模态分析的计算效率,且能避免Wilson-Ritz法中易于丢失低阶模态特性的不足之处。
A basic problem that will be met in the application of Wilson-Ritz vector method in the modal analysis of structures is discussed. This problem is how to define the space distribution vector of the pseudo-load,as there is no external load acting on the structure when the free vibration is studied. A special space distribution vector is suggested for avoiding the frequency omission phenomenon in normal Wilson-Ritz method when it is applied to calculate the modal characteristics of the structures,in especial,the structures are symmetrical. This space distribution vector is defined as the product of the mass matrix of the structure and a weighted function vector which includes two factors of the distance and the symmetry. Meanwhile, an iterative method for calculating the Ritz vectors is introduced to raise the computational precision. The results of two numerical examples show the efficiency of the method presented in this paper.
出处
《地震工程与工程振动》
CSCD
北大核心
1992年第4期40-47,共8页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金
