STV-6 Natural Frequencies and Mode Shapes of Straight Tubes

R. Sahu

This report discusses various methods that have been proposed to determine the natural frequencies and, where appropriate, the mode shapes of straight tubes. This forms the basis of assessing tube damage possibilities due to vibration in shell-and-tube heat exchangers. Tube vibration in heat exchangers is a well recognized problem at the present time. Any analysis of the problem rests on the accurate determination of the natural frequencies of the tubes. After a brief theoretical analysis of the vibration of single-span tubes, the report discusses the different methods used in the case of multiple span tubes. While commonly used method, mostly empirical, are described in detail, modern theoretical and computational methods are discussed in general. However, references given at the end should enable the interested reader to pursue any given topic.