Influence of a Deformable Contour Ring on the Nonlinear Dynamic Response of Cable Nets

The interaction between a cable net and its contour ring is investigated, regarding the nonlinear dynamic response of the system subjected to harmonic loads or wind action. Similarities and differences are highlighted between a network with fixed cable ends, accounting for rigid supports, and one with the cables anchored to a deformable ring, representing flexible supports. The sensitivity of the dynamic response of cable nets to their boundary conditions is demonstrated. Modelling the contour ring is proved to be indispensable, as it is responsible for new vibration modes, which may transform the entire behaviour of the net and modify the results with respect to the ones referring to the net with rigid supports. It is verified that the existence of the in-plane mode of the ring influences significantly the amplitude of the net oscillation for uniform spatial distribution of the load, while for antisymmetric spatial load distribution the presence of the ring does not alter significantly the net's dynamic response.