EXPERIMENTAL INVESTIGATION OF THE NONLINEAR RESPONSE OF A HANGING CABLE .1. LOCAL ANALYSIS

An experimental model of an elastic cable carrying eight concentrated masses and hanging at in-phase or out-of-phase vertically moving suppo rts is considered. The system parameters are adjusted to approximately realize multiple 1:1 and 2:1 internal resonance conditions involving planar and nonplanar, symmetric and antisymmetric modes. Response meas urements are made in various frequency ranges including meaningful ext ernal resonance conditions. A local analysis of the system response is made on the basis of numerous amplitude-frequency and amplitude-forci ng plots obtained in different ranges of the control parameter space. Attention is mainly devoted to the detection of the main features of t he regular motions exhibited by the system, and to the analysis of the relevant phenomena of nonlinear modal interaction, competition, and l ocal bifurcation between planar and nonplanar regular responses. The r esulting picture appears very rich and varied.