基于散斑干涉的光滑表面变形快速检测

针对目前光滑表面力学性能测试困难的情况,建立了一种改进的数字激光散斑干涉测量系统。首先通过新的散斑干涉光路设计实现散斑照射,同时采用空间载波傅里叶变换法,对光滑零件加载变形的动态散斑干涉图像进行处理,最后得到光滑表面的变形场分布情况。该方法不对被测表面进行任何处理,可实现光滑表面的高精度全场变形测量。实验结果表明:最大变形处为镜面板的中央,测得最大变形量分别为1.936、1.861和1.797μm,与中心变形预设值接近。该方法光路简单、测量方案切实可行,能够实现光滑表面变形的快速动态测量。

Fast detection of smooth surface deformation based on DSPI

In view of the difficulty of testing the mechanical properties of smooth surface, a measuring system based on improved digital laser speckle interferometry is established. First, speckle illumination is achieved by designing a new speckle interferometer optical path. At the same time, the dynamic speckle interferograms of the smooth parts are processed using the spatial-carrier Fourier transform method. Finally, the distribution of the deformation field of the smooth surface is obtained. This method does not perform any processing on the surface to be measured, which enables high-precision full-field deformation measurement on a smooth surface. The experimental results show that the maximum deformation is at the center of the mirror plate and the maximum deformation is 1.936, 1.861 and 1.797 μm, respectively, which is close to the preset value of center deformation. The method has simple optical path, a practical measurement scheme,which can realize fast dynamic measurement of smooth surface deformation.