Synchronicity Phenomena in Circular Cylindrical Shells Under Random Excitation

In many engineering areas, the structures are subjected to external forcing with a prevalent harmonic component in conjunction with significant likely non-deterministic contribution; moreover, the coupling between loading conditions and extreme environmental temperatures can lead to complex dynamic phenomena. In this paper, an experimental study on the nonlinear dynamics of a thin polymeric circular cylindrical shell, carrying a top mass, subjected to thermal gradients and random excitation is presented. Tests have been performed in controlled temperature conditions and the shell has been excited through an electrodynamic shaker. The experimental results pointed out that a broadband random excitation at the base of the shell can give rise to the synchronicity of the response to the resonance corresponding to the first axisymmetric mode of the shell; the vibration energy is conveyed to specific harmonics, some of which are outside and far from the excitation band.