烟囱自振特性的一种较精确分析方法

在工程实践中，高耸烟囱的力学模型大多被简化为离散系统，并使用近似计算的经验公式进行计算，存在着一定的误差。本文中用连续系统力学模型，并选用里茨第二法计算烟囱的自振特性。得到较精确的前三阶固有频率及振型。对不同高度的烟囱进行抗震设计和地震响应分析时，用本文中的特征值进行计算比较精确且简便。

A Precise Analysis Method for Free Vibration Characteristics of Chimneys

In engineering practices, the mechanics models of tall chimneys are usually simplified to discrete systems, and calculated with approximate methods and empirical formulas, thus inevitably yielding some errors. In this paper, the mechanics model for continuous systems is adopted and the second Ritz method is employed to calculate the free vibration characteristics of chimneys. As a result, the natural frequencies of the fore three orders ( i. e ., the first, the second and the third orders) and the vibration modes of chimneys are obtained with more precision. In case of aseismic design and seismic response analysis for chimneys with different heights, using the eigenvalues obtained in this paper to make calculation is more accurate and simple.