Abstract
In this paper the achievements of an intense experimental champaign, regarding shell nonlinear dynamics with and without fluid interaction, with thermal effects, subjected to harmonic or random excitations, is presented. Extreme thermal conditions, and high thermal gradients across the thickness of the shell cause important effects on the shell dynamics: a test setup has been developed to perform tests in climate chamber, in order to investigate the dynamics under different conditions, both for empty and a fluid-filled shells as well as for Newtonian and non-Newtonian (dilatant) fluids.
The response is strongly non-linear due to the couplings between fluid-structure-shaker which lead to a complex dynamic scenario. In the case of harmonic excitation, experiments show the onset of complex dynamics: subharmonic and quasiperiodic responses, Chaos. In the case of high-energy random excitation a synchronicity phenomenon was detected for particular thermal and loading conditions: a severe transfer of energy from a broadband excitation to almost harmonic response is experimentally observed; energy transfer to low frequencies was observed as well.
