声疲劳试验装置对试件低频振动响应的影响

本文利用边界钳定矩形薄板试件的声致振动实验结果和对该结果的理论分析,说明了在声疲劳试验中,试件的低频振动响应一般不仅仅取决于试件本身的性质及其边界条件,还要决定于使试件与声场耦合起来的试验装置,而且有时后者比前者更具有决定性的意义。文章在声疲劳试验系统的分析中,引入了电-力-声类比电路方法,这一应用可以半定量地估算系统中的各种因素对试件低频振动方式的影响,为指导声疲劳试验的合理设计提供了一种理论依据和手段。

Effects of installations on the low frequency vibration response of specimens in acoustic fatigue tests

In acoustic fatigue tests, it is often considered that the vibration response of a specimen in a progressive tube or in a reverberation rcom depends only on the dynamic characteristics and the boundary condition of the specimen, and has nothing to do with the test setup which couples the specimen to the corresponding sound field. By using the experimental results and the analysis of the acoustic-induced vibration of a boundary clamped rectangular thin plate with a currentlp used test setup in a progressive tube and in a re verberation room, this paper stresses that the effects of the setup on the low frequency vibration modes must not be neglected in some cases. In the theoretical explanation of the experimental results, the Rayleigh-Ritz method is firstly used to give several natural frequencies of low order; the an approach of electro-mechano-acoustical analogous circuit is introduced to yield the other resonant and anti-resonant frequencies in the response spectra. This approach can be applied to estimate the attribution of various parameters of a given test setup to the vibration response quantitatively, and it supplies a rational layout of acoustic fatigue tests with a theoretical basis and means.