【摘要】 <正> 为了便于叙述,我们首先定义几个特征量。 1.特征量a:它表示一个振幅值,即当振动物体表面上的点的振幅超过此值时,散斑亮度将发生明暗快速变化。这时在散斑干涉仪观察口处观察由这样一些点组成的区域时,只能看到一片光亮。 2.特征量b:它表示利用散斑干涉仪能够区别的散斑反差的振幅条件,即当振动更多还原

【Abstract】 In this paper a new experimental plan of measuring resonant frequencies of structures is given by use of speckle interferometer. Based on this plan, by continuons scanning in the needed bond of frequencies under conditions of decreasing the stimulating force step by step ,we can not only distingush two very close resonant frequencies,but also raise the measurement precision of resonant frequencies greatly.The theory, experimental steps and the applicable range about this plan are disscused in the paper.更多还原