Fundamental Frequencies of Long Prismatic Shells

The impact of the length of a shell on the fundamental frequencies of natural vibrations of a prismatic thin shell is studied in the paper. A thin cylindrical shell, the cross section of which is a regular polygon, is analyzed. Provided that the perimeter of the cross section is preserved, the influence of the length of the structure and the number of faces on the natural frequencies is examined. For limiting cases of the number of faces (shells with a square cross section and circular cross section), the results of numerical analysis in COMSOL and the analytical results are in close agreement with each other.