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 vibrationmodes 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.