Nonlinear Vibration Analysis Of Cable-Beam Model Of Single-Mast Guyed Tower

Torsional vibration is a special property of a single-mast guyed tower,which the vibration of the guy is coupled with the bending and torsional vibration of the mast.Traditional cable-beam coupling problem is only the coupling between cable vibration and beam bending vibration,while the research on the coupling vibration similar to the guyed tower has not been reported.Therefore,in this paper,the nonlinear vibration characteristics of a single-cable-beam model considering torsional vibration of a beam are studied for the first time in combination with the torsional vibration characteristics of a single-mast guyed tower.Static and dynamic theories of cable,bending vibration of beam and torsional vibration of shaft are studied.Considering the action of beam on cable in the cablebeam model as transverse end displacement excitation,the nonlinear vibration equation of cable under transverse end displacement excitation is derived,and the influence of excitation frequency,amplitude and damping on nonlinear vibration is studied.The coupled vibration equations of cable-beam model without considering torsional vibration of beam are derived.The nonlinear partial differential equations are discretized into ordinary differential equations by Galerkin method.The coupled vibration characteristics are studied by Runge-Kutta method.The coupled vibration equations of cable-beam model considering torsional vibration of beam are derived.The effects of parameter variation and torsional vibration coupling on nonlinear vibration are discussed.The results show that :(1)The initial in-plane disturbance of the beam has a great influence on the coupled vibration of the cable-beam model,and the small change will cause the drastic change of the in-plane amplitude of the cable,while the initial in-plane disturbance of the cable has a small influence on the beam.(2)When the cable-beam model vibrates under the initial disturbance in the plane of the cable,considering the torsional vibration of the beam and not considering the torsional vibration of the beam,the amplitude of the cable is basically the same,while the amplitude of the beam is increased.(3)Under the combined action of the initial in-plane and out-of-plane perturbations of the cable and the beam,the amplitude of the cable and the beam increases when the torsional vibration of the beam is taken into account.The vibration of cable and beam is high frequency.(4)Under the action of large initial torsional disturbance,a large range of nonlinear vibration appears both in and out of the plane of the cable,and the in-plane vibration of the beam takes the form of high-frequency and low-amplitude vibration.