Vibration Control Of Large Net Structures Using Wave Method

Because of the features of large scale and high degree of freedom,the net structure does not vibrate as a whole as soon as the stimulations act on it.Instead,the disturbances propagate along the strings in the form of traveling waves.The strong wave feature of that kind of structure make it difficult to do the dynamic analysis and vibration control by using traditional modal method.In order to solve this problem,in this paper a wave-based dynamic analysis method for net structures is proposed.Then,on the basis of this wave-based method,we study the wave-based vibration control of the net structures.Firstly,based on the traveling-wave form solution of the 1-D wave equation,the frequency responses of every continuous string separated from a net structure can be described by two independent wave components.By solving all the junction and boundary coordination equations constructed by wave components together,the analytical responses of the net structure can be achieved.The wave-based analysis method,can get the analytical responses of the net structures.Then,a wave-based method combined with transfer matrix method is proposed,which makes it more convenient and efficient to deal with large structures than FEM.By combining wave-based analysis method with wave-based boundary control,the wave-based boundary control strategies toward net structures under different disturbance sources are achieved.The wave-based boundary control strategies can help to restrain the resonance and speed up the decay of free vibrations by absorbing the incident wave,Finally,in order to make it possible to control net structures' vibration by applying control on junctions,a wave-based junction control method is offered.Then,with the help of the wave-based analysis method,wave-based junction control strategies to disturbances from different locations are obtained as well.