Sound Radiation Analysis of Stiffened Composite Panels
|關鍵字:||聲傳;加勁;複合材料板;揚聲器;振動;振幅與相角;sound radiation;stiffened;composite panel;loudspeaker;vibration;amplitude and phase|
The effects on sound radiation of composite panels with different stiffened designs are studied in this thesis. This study is used to design the stiffened composite panels with enough stiffness which can avoid the fluctuation of sound pressure. By investigating the differences among the behaviors of sound pressure responses of four types of stiffened plates and an unstiffened one, we obtain a structural design which can effectively modify the stiffness of a plate structure and its sound radiation behavior. For theoretical analysis, the simulation models of radiating panels with different designs of stiffeners were constructed using the software ANSYS. The amplitudes and the phases of these panels were obtained from the analyses of the simulation models using given system parameters such as spring constants of suspension and damper, the thrust of the voice coil and the damping ratio of the loudspeaker system, which were measured from experiments. Then, we use the amplitudes and the phases in the program of calculation of sound pressure level to simulate the behaviors of sound radiation of the loudspeakers. Through the comparison between the curves of sound pressure response measured by the sound measurement system MLSSA and the ones simulated by computer, we can find out the reason causing the drops in sound pressure curves and the direction to improve the loudspeaker system further. Finally, the discrepancies between the results of experiment and these of simulation were discussed.
|Appears in Collections:||Thesis|