控制振动板结构的体积位移是降低结构总声功率的一种有效策略。本文以工程常见四端位移为零的振动板为例,提出一种新的压电式传感器的设计方法测量体积位移。利用正弦函数展开近似表示固定板振动位移,通过设计特殊形状的PVDF压电薄膜,使PVDF输出信号为所需要的振动结构体积位移。结果表明这种体积位移传感器不仅适用四边简支、四边固定以及介于两者之间的边界条件板结构,而且作为一种误差传感器测量振动结构体积位移是可行的。并对实验数据进行了分析比较。
Controlling the volume displacement of vibration plate has previously been shown to be a good strategy to reduce its overall sound radiation at low frequency. With a shown example of the pinned-pinned plate, a new piezoelectric sensor design is presented to measure volume displacement. Displacement of vibration structure is expressed by a sinusoidal function. By designing PVDF film of particular shape, the volume displacement of vibration plant can be obtained. It is shown that the sensor design can not only be applied for vibrating plates with simply-supported, clamped-clamped and some combinations of pinned and clamped boundary conditions, but also be used as an error sensor, through which it is feasible to measure the volume displacement of vibrating structure. The analysis and the comparison between the numerical results and the experimental data are given.