基于声辐射模态获取振动结构体积速度和能量分布

控制振动板结构的体积速度是降低结构总声功率和振动能量的一种有效策略。在中低频时,体积速度与第一阶声辐射模态伴随系数近似成正比。在振动平板上测量少数点振动速度分布,利用声辐射模态正交性质,通过求解欠定方程组,得到所需要的声辐射模态伴随系数,从而得到体积速度和振动能量。数值分析表明,得到的体积速度和振动能量与理论值一致,并且利用上述方法可设计一套结构简单、操作性较强的控制系统。

Acquisition Volume Velocity and Energy Distribution of Vibration Structure Based on Radiation Modes

Controlling the volume velocity of vibration plate has previously been shown to be a good strategy to reduce its overall sound radiation and vibration energy. The shape of the first radiation mode corresponds to the volume velocity of the plate at the low frequency. By measuring the vibrating velocity distributions at few points of a plate and solving the underdetermined equations of the acoustic radiation mode expansion, the desired adjoint coefficients of radiation modes as well as the volume velocity and energy of vibration structure can be obtained. Numerical analysis indicates that the volume velocity and the vibration energy are consistent with the theoretical values. In addition, the above theory can be used to design the simple and highly operable active controlling system.