利用激光散斑相关的非接触式随机振动特性测量

所发展的测量随机振动的方法,是测量由物体表面一个点漫射形成的散斑场的相关统计特性.根据激光散斑运动规律,这个相关统计特性实时地反映该点的位移或转角的时间历程.由所记录的相关信息,通过频谱分析,可以得到运动的频城特性参数,这种方式是非接触式光测方法,对物体无任何附加质量的影响.本文以铜梁和钢梁为例.测量了冲击力作用下,梁的动态响应和频谱.

Noncontact Measurement for Random Vibration by Laser Speckle Correlation Technique

The presented method for measuring random vibration is based on the statistical correlation of laser speckle come from a point of diffusing reflective object. According to the laser speckle movement formula, the statistical correlation relates to the displacement or rotation of the diffusing point in real time. The recorded correlation information can provide the charasteristic parameters of the vibration in frequency domine through frequency analysis. By using the noncontact optical method, there is no need to add an extra mass to the object. In this paper, the dynamic responses and their spectra for a copper beam and a steel beam subjected to impact load were measured as examples.