Frequency Analysis of Self-supported Steel Chimneys

Chimneys are the most significant industrial components used to release toxic and undesirable fumes into the airspace. Various kinds of chimneys are used in industries, such as RCC chimneys, masonry chimneys, steel chimneys, etc. The work focuses on the frequency analysis of self-supported steel chimneys using single-degree-of-freedom (SDOF) system, multi-degree-of-freedom (MDOF) system, and Dunkerley’s method. The two chimneys of heights 275 and 120 m having varying diameter and thickness, varying diameter and uniform thickness, and uniform diameter and thickness are considered. The frequencies are evaluated and compared with the above methods for all the chimney models. It is observed from the results that all three methods considered in the current study approximately give the same values of fundamental natural frequency. The chimney model with uniform diameter and thickness and the fundamental frequency were observed to be more as compared with other two models.