弯曲振动薄圆板的辐射效率

Radiation efficiency of a thin circular plate vibrating flexurally

通过对激励点进行面平均,研究了点简谐力激励下圆板在固定及简支边界条件下弯曲振动时的模态辐射效率及平均辐射效率,分析了圆板的厚度、阻尼损耗因子、半径及边界条件对其平均辐射效率的影响规律。研究表明:圆板在点简谐力的激励下,其模态辐射效率及平均辐射效率在中、低频段随频率的增高而增大,而在高频段二者则均趋近于1;圆板的平均辐射效率与激励力的大小及位置无关,而由圆板的厚度、阻尼损耗因子、边界条件及半径所决定;当频率一定时,圆板的平均辐射效率在中频段随着其厚度、阻尼损耗因子的增大及半径的减小而增大,而在低频段,则随着半径的增大而增大;固定及简支边界条件下圆板在全频段的平均声辐射效率基本相同。

By taking an average over all possible points excited by simple harmonic force,the modal radiation efficiency and the average radiation efficiency were derived for a point-excited circular plate with clamped and simply supported boundary conditions.The numerical results of the modal radiation efficiency and the average radiation efficiency were shown,and the influence factors of the average radiation efficiency were analyzed.The results showed that both of the modal radiation efficiency and the average radiation one increase with increase in frequency within low and middle frequency bands,while within high frequency band both of them approach 1;The average radiation efficiency is determined by thickness,damping loss factor,boundary condition and radius of the circular plate,but independent on exciting force and its position;within middle frequency band the average radiation efficiency increases with increase in thickness and damping loss factor,but decreases with increase in radius;within low frequency band,it increases only with increase in radius.The average radiation efficiencies of the circular plate under clamped boundary condition and simply supported one are basically the same over the whole frequency band.