用白光散斑的直接记录法测量曲面变形

本文提出以物体表面精细光学结构在白光照射下辐射率随机分布函数作为散斑场,以全息软片为记录介质,采取无镜头成象技术,得到宽频域的散斑底片,并用有一定带宽的准单色光进行全场分析,测量可展曲面变形,其结果不仅具有较高的灵敏度,较大的灵敏度调节范围,而且其中的准备过程、记录过程和分析过程比现有的各种测量曲面变形的散斑法都要简单,该方法将可展曲面变形问题简单地转化为平面问题处理,保留了白光散斑直接记录法在测量平面变形时的全部优点,并能脱离暗室在工程现场中应用。

STRAIN DETERMINATION ON CURVED SURFACES BY OBJECTIVE WHITE LIGHT SPECKLES

A close-range objective white light speckle method has been used for strain determination on single curved surfaces. The speckle field is not the artificially printed random dots but only the radiance distribution of object surface which was slightly treated before the test to produce fine structure of optical details. The holographic film in stead of holographic plat is clamped closely 10 the curved surface when illuminated by a flash light. Whole field fringe patterns are obtained with high sensitivities and large adjustable range. There is no longer a requirement to relate the speckle movement on image plane to the object surface. Defocus problem has been avoided. It can be practically applied to engineering problems with considerable convenience because of the very simple recording system aad little demand for environmental stability.