On Vibration of a Thin Cylindrical Shell, which is immersed in Water and subjected to a Combined Stress

Abstract

The frequency (ω) of free vibration of a thin elastic cylindrical shell was obtained by a theoretical calculation. The effect of virtual mass of water filled inside (or outside) the shell, the effect of external (or internal) normal pressure, together with the effect of axial compreesive (or tensile) force are taken into account. It is inferred, from the results of calculation, that : -(a) The effect of axial force is rather small in comparison with the effect of virtual mass of water and that of normal pressure, so long as the shell whose length is larger than its diameter is concerned. (b) Under such a way of loading, in which the ratio of axial force to normal pressure is kept constant, the relation between the angular frequency ω and the pressure p becomes practically a straight line. It is suggested that, taking advantages of this fact, a method of non-destructive test for collapsing pressure of thin cylindrical shells (such as a pressure hull of a submarine) may be possible.