Dynamic stability of a base-excited thin orthotropic cylindrical shell with top mass: Simulations and experiments

Considering both an experimental and a numerical approach, the dynamic stability of a harmonically base-excited thin orthotropic cylindrical shell carrying a top mass is examined. To be able to compare the experimentally obtained results with numerical results, a semi-analytical coupled shaker-structure model is derived. Using the semi-analytical model, it is shown that the dynamic stability analysis of the base-excited cylindrical shell with top mass should be concentrated near a low frequency resonance, corresponding to a mode, in which axial vibrations of the (cylindrical shell with) top mass dominate. In this frequency region, the shell may exhibit an aperiodic beating type of response, if some critical value of the amplitude of the harmonic base-excitation is exceeded. This beating response is characterized by severe out-of-plane deformations. The experimental results qualitatively confirm the numerical observations.