新型三维位移场测试理论及系统研究

Newly designed experimental system for 3-D displacement measurement

研究建立了可同时进行三维位移场测试的新型光测力学实验系统。平面位移测试基于云纹干涉方法 ,但采用与普通云纹干涉不同的光路系统 ,利用试件光栅和平面反射镜组形成的两次衍射 ,使平面位移干涉条纹倍增 ,测量灵敏度是普通云纹干涉的 2倍。采用泰曼 /格林干涉光路测量离面位移。整个系统具有构造新颖、便于调节、位移场条纹对比度高等特点。用波前干涉理论 ,建立了位移条纹方程式 ,与由多普勒频移原理建立的位移条纹方程式取得了一致的表达结果。通过微电子器件三维热变形的测量 。

In this study,a newly optical interferometry method for 3-D displacement measurement is developed.The system is a combination optical system of four beams quasimoire interferometer with Twyman-Green interferometer.The in-plane displacement can be measured by two times diffracting between the specimen grating and reflect mirrors,resulting in double sensitivity higher than that of a conventional Moire Interferometer.The advantages of the optical set-up are structure novelty,and the fringe patterns of the displacement fields shown high contrast and spatial resolution.The fringe governing equations are derived based on wavefront interference theory,and have the same results from that of the Doppler frequency shifts.Then some experiments are carried out to verify the system.