摘要
本文将一特殊布置的云纹干涉系统和一垂直入射试件栅的麦克尔逊干涉系统组和起来,利用云纹干涉系统测量两个面内位移分量U、V,垂直入射的麦克尔逊干涉系统测量离面位移分量 W。调节云纹干涉系统中入射光的入射角,使正、负一级衍涉波的传播方向偏离开试件栅法向一微小角度,从而使一级衍涉波的频谱点与麦克尔逊干涉系统中的零级衍涉波的频谱点在频谱面上分开。利用小反射镜的反射来改变一级衍射波的传播方向,从而使我们在三个彼此分开的成像面上同步实时观测到三维位移场的条纹图。文中给出了严格的理论推导和实验验证。
A specially arranged moire interferometry is proposed for measuring 3-D displacement fields in real time simuraneously. An optical arrangement is developed, which consists of three interferometry systerms: one normal incidence holographic interferometry and two Moire interferometry arrangements. An experimental demonsf-ation is conducted using a disc specimen with a high frequency cross line grating on its surface. The normal-mcidence holographic interferometry is used for obtaining the out of plane displacement field W of the specimen grating. In-plane displacement field U in X direction is acquired by the dual-beam Moire interferometry arrangement in XOZ coordinate plane. Beani carrying U displacement field information is deviated a little from the normal of the specimen,grating, in which beam carrying only W information emerges essentially. The two beams are collected by a camera lens and focused on two spectrum pom's which are separated from each other on spectrum plane. A minor mirror is situated on the spectrum plane and the propagating direction of the U beam is changed by the reflection of the mirror. The displacement pattern of U field is focused on an image plane-Image Plane Ⅱ-through the reflection of the minor minor, while W beam remains in its propagating direction a nd W displacement pattern is focused on another image plane-Image Plane Ⅰ. Duplicated arrangement in the perpendicular plane YOZ gives Ⅴ displacement field pattern in Y direction which is observed on the third image plane-Image Plane Ⅲ. The three image planes are completely separated from one another and all the three observations are in real time simutaneously. Rigorous theoretical analysis is given. Experimental demonstration is conducted successfully and displacement patterns are obtained with excellent fringe conerast.
出处
《力学学报》
EI
CSCD
北大核心
1991年第5期589-594,T001,共7页
Chinese Journal of Theoretical and Applied Mechanics
关键词
三维
位移场
云纹干涉法
3-D, displacement, Moire 1 nterf erometry, real time, measurement
