贴片云纹干涉法测量离面位移及振动

将全息胶片用特种胶粘贴到试件表面,用加载前后两次曝光法得到全息云纹,然后使胶片与测试对象分离后进行处理,这种可分离处理的贴片云纹干涉法在面内位移及应变场测量中已获得成功应用。它具有实验周期短、工艺简单、测量精度高等优点。本文首次提出采用非对称双光束入射贴片云纹干涉法,在忽略较小面内位移影响的前提下可获得离面位移及振幅场。文中用付里叶光学验证了面内位移定量公式,推导了离面位移及振动的计算公式,并对测量精度及灵敏度作了讨论。最后给出了对悬臂梁挠度及矩形板横向振动的测试结果。本文的工作扩大了贴片云纹干涉法的应用范围,对工程实际应用具有一定价值。

Moire Interferometry of Sticking Film for Out-of-Plane Displacement and Vibration Measurements

The holographic film is stuck on the surface to be measured. The film is exposed before and after loading, and two gratings are recorded. A clearly visible moire pattern may be obtained by developing, fixing and illuminating the film. This technique, which is extremely attractive for in-plane displacement measurement, is simple and has a high sensitivity. With this method the experimental cycle may be shortened and expense reduced. This paper first presents a method to measure the out-of-plane displacement and vibration by moire interferometry of sticking film. The principle of the measurement is introduced. The formulas are deduced and used to analyze the displacement and vibration mode. Experimental results show clearly that moire interferometry may be applied to an extensive range of deformation and vibration measurements.