Research On Vibration And Noise Active Control Methods Of Beam And Plate

The traditional passive control method control effectively in the high frequency, but it control ineffectively in the low frequency and in the frequency domain the active control method can controll the low frequency well.Firstly,this paper is based on the theory of structure vibration mode, the active vibration control of structure is studied in the frequency domain.Then the active control is applied to the structural vibration contro in the time domain. At last, the acoustic radiation mode theory is applied to the active control of sound radiation. The following work is done in this paper:In the frequency domain, based on the finite element method establish the finite element model of simple supported beam and plate and analyze. According to the structure vibration mode method, calculate the vibration mode of beam and plate, deduce the relationship between the mean square vibration velocity and the excitation force, obtain the vibration control force. On the basis of this, established the model of structure vibration control, and analyze the influence of the number and position of control force on the control effect.In the time domain, obtain the vibration response of the structure under the action of excitation force, and the structural vibration velocity in the time domain is obtained. According to the goal of vibration control system establish the vibration control model, the vibration control method based on he minimum mean square(Fx LMS) algorithm and the least square lattice adaptive filter(QRD-LSL) combine the lattice filter is used to the vibration control. The influence of the parameters of the control algorithm, the position of the control force and the two kinds of different control algorithms are studied.Based on the acoustic boundary element integral equation, obtain the expressions of the acoustic radiation power and radiation efficiency.Analysis the acoustic radiation modes and radiation efficiency of beam and plate. The relationship between the acoustic radiation power and the excitation force is obtained by using the boundary element method, and obtain the size of the control force by using the Rayleigh integral. According to the acoustic radiation control target, the model of the acoustic radiation control is established, and the influence of the number and position of the control force on the control effect is studied.