双参考光全息—散斑干涉术的原理和实验

本文用统计光学方法对双参考光全息——散斑干涉术进行了详尽的理论分析,给出了全息和散斑干涉场区域平均光强分布与光学系统主要参数及三维变形场各分量之间关系的解析表达式,进而讨论了离面位移和面内位移测量的上、下限,最后还给出了有关的实验结果。     

超声散斑数字相关法应用于刚体面内转动测量的研究

在激光数字散斑相关法测量理论的基础上,阐述了超声散斑相关法测量的基本原理,并建立了相应的超声散斑数字相关实验分析系统。在实验分析时,首先应用模拟测量的方法对刚体面内转动对散斑场相关性的影响进行了分析;然后应用实验测量的方法再对此进行了分析;最后对刚体未知面内转角进行了实测。实验结果表明,刚体面内转动可测量的最大转角为9°,当转动角度为10°时,误差大于9%。实验中分别应用了爬山搜索法和相关系数拟合法来分别搜索整像素的位移和亚像素的位移。     

超声散斑数字相关法应用于体面内转动测量的研究

在激光数字散斑相关法测量理论的基础上,阐述了超声散斑相关法测量的基本原理,并建立了相应的超声散斑数字相关实验分析系统。在实验分析时,首先应用模拟测量的方法对刚体面内转动对散斑场相关性的影响进行了分析;然后应用实验测量的方法再对此进行了分析;最后对刚体未知面内转角进行了实测。实验结果表明,刚体面内转动可测量的最大转角为9°,当转动角度为10°时,误差大于9%。实验中分别应用了爬山搜索法和相关系数拟合法来分别搜索整像素的位移和亚像素的位移。     

光栅大错位数字散斑干涉系统及其应用研究

本文用统计光学理论简要简述了大错位数字散斑干涉的原理及特点,并在此基础上首次提出利用光栅作为错位元件的光栅大错位数字散斑干涉。该方法具有与全息干涉计算相同的灵敏度,光路简单、结构紧凑,波像差小,防震要求低等特点,文中对该方程进行了详细的原理分析与介绍,利用其对典型试件受均布载荷下的离面位移场进行测量,通过理论值与实验结果的比较,表明该方法的可行性,该方法拓宽了散班干涉技术的适用范围,为实际生产中的     

基于电子散斑干涉法的高弹性连轴器挠性杆位移分析

本文重点讨论了应用电子散斑干涉法测量弹性元件的挠曲线的方法.将电子散斑测量离面位移的光路引入到高弹性连轴器挠性杆的横向弯曲变形测量中.新的离面位移测量光路并结合相移技术是其特点.首先采用类似于麦克尔逊式光路的方式将物光和参考光垂直分布,使得离面位移的结果是直接并且是纯粹的获得;其次,固体泵浦激光的相干长度很长,从而在设计光路时带来了便利,光路可以很紧凑而不考虑物光与参考光的光程差;最后,在参考光路中引入精密的PZT相移器,从而实现了位相技术,使得测量的结果能数字化输出.电子散斑干涉方法在光学非破坏性检测领域得到了广泛的应用,采用电子散斑干涉技术可以测量物体的变形、位移、振型等.该方法具有实时显示、全场非接触测量、精度和灵敏度高、采用位相技术可以方便的实现测量结果的数字化等优点.本文采用电子散斑干涉结合相移技术,得到了的数字化结果,再和有限元模拟计算进行了比较,证明了方法的正确性.     

数字散斑剪切干涉及偏转平台法相移系统研究

在传统的剪切电子散斑干涉中 ,直接观测到的是干涉条纹图样。因此 ,如何将位移导数场的定量信息从剪切电子散斑干涉条纹图案中提取出来 ,一直是人们关心的问题。本文运用传播光矢量对数字散斑剪切干涉的条纹形成作了理论解释 ,使其物理意义更加清晰。理论分析表明 ,物体的微小偏转可引入线性附加位相。因此 ,通过连续偏转物体可实现剪切电子散斑干涉的相移。本研究通过计算机控制载物平台的精细旋转实现相移 ,结合传统的数字散斑剪切干涉技术以及四步相移算法 ,实现了数字剪切散斑干涉相移系统。利用该系统进行了中心加载、周边固定的圆盘的典型实验 ,实验结果表明该系统可以方便有效地提取出位移导数场的定量信息。     

散斑全息干涉法测量面内位移和应变

测量面内位移和应变有很多方法,诸如莫尔条纹法、全息干涉法、激光散斑干涉法等属于近代光学方法。其中莫尔条纹法需要在试件表面布上极细的网格,这在工艺上较难;而全息干涉法又需沿不同方向进行全息照相,要求较高,数据处理的程序也较繁复.最近国外采用激光散斑干涉来测量面内位移和应变,发展很快。激光散斑干涉法亦有多种。成象散斑干涉是记录被相干光照明的物体经透镜成像后所形成的具有斑点图信息的物体象,照明光可用单光束或多光束:光栏也可以是单孔或多孔。我们曾采用单光束和单孔成象的散斑干涉法对游标盘的转动进行了定标试验。另一种散斑干涉法是直接将感光片和被测物表面贴近,并牢靠地固定其相对位置.再用一束准直激光直接从感光片背面射入。由于照明光与物体表面的漫反射光是从接近180°的方向射到感光层,因而感光片记录的信息中不仅有斑点图信息,而且还包含有能实现白光再现的全息图信息,我们暂且称其为散斑全息干涉法.本文主要介绍散斑全息干涉的物理原理和它的实验方法,并利用杨氏干涉法对游标盘转动后的位移量定标和对单向拉伸的矩形板中的圆孔应力集中系数进行了定标,取得了实验结果。此外,还指出了散斑干涉法的缺点和局限性。     

用散斑和全息干涉法测量汽车前桥的位移

本文分别用散斑和全息干涉法测量了汽车前桥模型的面内和离面位移.实验表明,所用方法简便可行、且精度较高.     

测量小区域三维位移场的显微全息干涉与散斑干涉

1.引言 Solid、Gilbert、Sciammarella、Satour Toyooka以及Jerome等人提出的各种测量三维位移场的全息干涉方法.在试验技术和定量分析方面都比较复杂.(?)的工作虽是一种很好的测定三维位移场的简单方法,但失去非接触式测量的优点.本文利用象平面全息干涉与散斑干涉同轴结合的方法,在一张底板上同时记录了面     

用直接散斑技术测量复合材料试件的面内位移

直接散斑法用来测量带中心圆孔复合材料条状试件在拉伸载荷作用下的面内位移分布,采用镜面移植技术,提高复合材料试件表面的反射性能,从而得到高质量的散斑干涉干板,在分析散斑干涉干板时,由于得到的全场位移分布条纹频率的可调性,使此方法测量范围很宽,由弹性应变到塑性应变,直接散斑法测量的结果与云纹法得到的结果相符合。     

Use of electronic speckle interferometry for recording nanodisplacements

Advancement of nanomechanics and nanotechnologies assumes creation of adequate tools for measuring displacements in the nanoscale range. In the present paper, for these purposes we propose to use the method and hardware of electronic speckle interferometry, which have several advantages over the other known measurement means. We present an idea based on which the method of electronic speckle interferometry, primarily designed to be used to measure displacements in the submicron range, can be used to measure displacements that are hundreds of times smaller, i.e., of the order of 1 nanometer. We consider the theoretical justification of this idea and the program algorithm for its implementation and describe the methods, the test specimens, and the results of experimental metrological test of the possibility of measuring displacements in the nanoscale range by using the existing model of the electronic speckle interferometer.     

Impact-induced transient deformation analysis by means of digital speckle pattern interferometry

Transient in-plane displacements generated in a metal plate subjected to impact loading are measured using a pulsed digital speckle pattern interferometry system. Two separated speckle patterns produced by a ruby laser that freezes the object motion are recorded using a CCD camera and stored in a frame grabber. Transient displacements are evaluated by digital analysis of the fringes generated by the subtraction of these speckle patterns. The computer used for image processing is also utilized to control image acquisition and to synchronize the laser pulses to the CCD camera and the object position. Experimental results are compared with numerical calculations obtained using the finite-element method.     

In-plane and out-of-plane displacement measurement by ultrasonic speckle correlation method (USCM)

When an object moves, ultrasonic speckles backscattered from its surface will follow the object to move. From the Kirchhoff diffraction theory and the correlation principles of random signals, the necessary condition for keeping the correlativity between the speckle fields before and after the objective displacement was deduced. Based on this condition, the formulas for the relationship between the speckle displacement and the objective displacement were obtained. Practical measurement was performed. Ultrasonic digital speckle correlation method was used to measure the in-plane displacement and out-of-plane displacement of an object. The displacements of the objective surface were evaluated after the displacements of the speckles were determined.This method can be also used to measure the displacements of an inner objective surface. A mountain-climbing search method was proposed, which enabled us to find the maximum correlation coefficient in the correlation operation quickly and efficiently. The experimental results showed good agreement with the theoretical predictions.     

红宝石脉冲激光动态光力学方法研究与进展

本文提出了瞬态图像采集技术和电磁脉冲加载装置。应用红宝石脉冲激光光源,介绍了动态全息光弹性、动态散斑干涉、动态云纹干涉、水下爆炸全息干涉、动态电子散斑干涉和动态数字散斑相关等多种方法的测试原理和测试技术。为动态位移场、应变场和应力场的定量分析提供了广泛的应用前景。     

红宝石脉冲激光动态光力学方法研究与进展

本文提出了瞬态图像采集技术和电磁脉冲加载装置。应用红宝石脉冲激光光源,介绍了动态全息光弹性、动态散斑干涉、动态云纹干涉、水下爆炸全息干涉、动态电子散斑干涉和动态数字散斑相关等多种方法的测试原理和测试技术。为动态位移场、应变场和应力场的定量分析提供了广泛的应用前景。     

撞击载荷下数字散斑干涉法中位相的自动计量

在撞击载荷下的数字散斑干涉法（DSPI）中，本文联合应用加法和减法两种模式提出了位相测试技术，以矩形板对称轴承受撞击集中载荷为例，测量了位移场的位相分布，为了采集红宝石脉冲激光形成的数字散斑场，提出瞬态数字图像采集技术。     

Evaluation of finite-element calculations in a part-circular crack by coherent optics techniques

Two techniques, speckle photography and holographic interferometry, were used to test three-dimensional finite-element calculations in an internally pressurized cylinder with an external part-circular crack. Opening displacements along the crack line were measured by speckle photography. Radial displacements were obtained from holographic fringe patterns. Good agreement between experimental and numerical data is obtained. Stress-intensity factor variations along the crack front are calculated from numerical results.     

Stress analysis by combination of holographic interferometry and boundary-integral method

The paper describes a hybrid experimental and numerical method analysis of bodies. It consists of the experimental method of double-aperture speckle interferometry and the boundary-integral method. The interference patterns allowing evaluation of the displacement vector are obtained by the speckle interferometry. The boundary displacements obtained experimentally are conveniently used for the calculation of stresses in the body by the boundary-integral method. Some examples bear witness of the effectiveness and accuracy of the hybrid technique.