Study On Vibration Control Method Of Large Flexible Cable-net Structures Based On Wave Theory

With the increasing size of the cable-net structures, the dynamic response of the structure dose not spread to the entire structure immediately when the structure is subjected to shock or disturbance, and the wave features of the structures is more significant than the vibration features. The vibration of the structures can be controlled when wave response and energy be suppressed. In this paper, we consider the dynamic response of the structure under local perturbation as wave propagation in the structure, and propose a method of structural dynamic analysis by using wave theory. Then wave control law is designed in the frequency domain, and the vibration control of cable-net structures can be finally achieved. The major works of this paper are as follows:1. The vibration of strings in the cable-net structure is regarded as two waves propagating along opposite directions. Then by combining the propagation relationship, continuity conditions, equilibrium conditions and boundary conditions, the wave response of the structures can be obtained. This theory can be applied on the structures with large-scale, different configurations and different materials. Transfer matrix method is also proposed based on wave theory. Compared with traditional methods, the method can describe the vibration characteristics of large flexible structures more accurately and conveniently.2. The scattering matrix of the joins can be obtained by establishing the continuity conditions at the joints. Then the rules of incident waves and reflected waves are determined. Furthermore, the total power flow of any position can be obtained through using Parseval’s theorem and the power flow expression of continuous structure and joints is obtained.3. The wave response of single point is selected as target function, and it can be controlled with numerical simulation and experimental investigation. Then the local or global vibration control of cable-net structures can be achieved by using the total power flow.