ANALYSIS OF INPLANE NONLINEAR RESPONSE OF CABLES THROUGH BIRFURCATION

Nonlinear responses of the cable through bifurcation under inplane forcing are analyzed in the present paper. Two different responses, that is the anti-symmetric response of the cable which is supported at the same level under symmetric forcing and subharmonic responses are treated. The equation of motion of the cable is solved by the Galerkin method and the harmonic balance method. From the results of numerical examples, the frequency range where the anti-symmetric response exists varies with the sag-to-span ratio and its width is broad in the particular sag-to span ratio. The secondary unstable region is important compared with the primary unstable region. Subharmonic responses with order 1/2 and 1/3 are also obtained. The subharmonic response with order 1/2 only in the case of the cable. This response is important for the cable whose quadratic nonlinear terms are predominant.