Dynamic Stability of Cylindrical Shells Under Step Loading

A study has been made to determine the dynamic stability of an imperfect circular cylindrical shell subject to a step loading in the axial direction. In the analysis, the radial displacement of the shell is approximated by a finite degree-of-freedom system. The dynamic analysis includes not only the effect of the radial inertia, but also, in an approximate manner, that due to the axial inertia. The critical loads are determined by numerical integration of the equation of motion. Compared with the static case, there is a significant reduction of the dynamic buckling load for the high wave number range of the radial modes. It is concluded that due to frequency coupling between axial and radial motions, the axial inertia plays an essential role in characterizing the dynamic instability of a finite length shell.