共查询到19条相似文献,搜索用时 46 毫秒
2.
三维变形可以转换为应力/应变分布,是材料性能测试和结构可靠性分析的关键参数。在众多三维变形测量技术中,数字散斑干涉技术可以高精度地测量三维变形信息,在航空航天、汽车、先进制造、土木工程和生物医学等行业发挥着十分重要的作用。从散斑干涉基本原理出发,详细介绍了几类三维变形散斑干涉测量技术,并分析比较各类方法的优缺点;同时介绍了散斑干涉三维变形测量技术的国内外研究进展和最新应用;最后展望了散斑干涉三维变形测量技术在动态同步测量、测量系统简化以及应用范围扩宽等方面的发展趋势。 相似文献
3.
4.
5.
为了满足无损检测中复合材料在复杂载荷下多参数变量评估的需求,提出了一种基于光路复用的双功能数字散斑干涉系统,能够同时实现数字散斑干涉和数字剪切散斑干涉测量功能.通过控制其中一个反射镜-波片组合,当该组合离位时,构成数字散斑干涉测量光路,实现离面位移测量;当该组合在位时,构成数字剪切散斑干涉测量光路,实现离面位移空间梯度的测量.测量过程中只需简单切换该组合的位置就可以实现单次加载下被测物体表面离面位移及其空间梯度的同时测量.该系统光路结构简单、切换效率高,能够同时获得高质量的位移及空间梯度测量结果.实验证明,双功能数字散斑干涉系统既具备高抗干扰能力,又具备高灵敏度测试能力,适合复合材料无损检测现场使用. 相似文献
6.
相位调制数字散斑干涉术 总被引:2,自引:2,他引:0
提出一种可绕Z轴转动的粗糙平板(参考物体)实现相位调制,该方法在不改变电子散斑干涉术(ESPI)或数字散干涉术(DSPI)系统装置的情况下,可用于微小离而位移场(例如最大离面位移为λ)的测量,以及复杂形变的离面位移场的自动测量。 相似文献
7.
8.
提出了一种新的剪切散斑干涉方法─—二次波面干涉的剪切散斑干涉计量术.这一方法将被测物体变形前后波面的第一次干涉信息分别储存在两张全息干板上,通过光学信息处理实现波面的第二次干涉.两次波面干涉分别消除了位移和位移的一阶导数场对波面位相的影响,得到仅反映位移二阶导数场的条纹图. 相似文献
9.
本文叙述了一种用于测量漫射表面变形的使用偏振相位偏移技术的电子散斑干涉术.由于采用共光路光学相位偏移技术,因而具有较高的稳定性;用计算机图像处理可精确地获得相位图;用去包裹技术(unwrapping)可直接得到表面变形的精确数据. 相似文献
10.
11.
This study proposes an image processing method to improve the quality of interference fringes in mode-shape measurement using temporal speckle pattern interferometry. A vibrating piezoelectric plate at resonance was investigated, and the full-field optical information was saved as a sequence of images. According to derived statistical properties, an algorithm was developed to remove noise from both the background and disturbance, resulting in high-resolution images of excellent quality. In addition, the resonant frequency and mode shape obtained using the proposed algorithm demonstrate excellent agreement with theoretical results obtained by the finite element method. 相似文献
12.
Volume-grating phase-shifting digital speckle pattern interferometry used for measurement of out-of-plane displacement field 总被引:1,自引:0,他引:1
A new digital speckle pattern interferometry, called volume-grating phase-shifting digital speckle pattern interferometry, is discussed in this paper. The out-of-plane displacement field of a bent plate can be quantitatively measured using volume-grating phase-shifting digital speckle pattern interferometry proposed in this paper. Theoretical and experimental results, as well as absolute errors, are given. 相似文献
13.
When the Hilbert transform method is used to recover the phase distribution in temporal speckle pattern interferometry, the influence of the fluctuations of the bias and the modulation intensities on the calculated phase must be driven heuristically. In this paper we show that the Empirical Mode Decomposition method can overcome these drawbacks and consequently introduces an improvement in the evaluation of the phase distribution. An example is used to illustrate the phase measurement improvement that can be obtained by the application of the proposed approach. 相似文献
14.
In this paper, the time sequence phase method (TSPM) has been applied to measure the displacement caused by low-frequency vibration in temporal speckle pattern interferometry (TSPI). The principle is that by capturing the temporal speckle patterns related to the object vibration, the whole-field displacement responses (amplitude and phase) of the vibrating object can be calculated through scanning these fluctuations. Thus, quantitative measurement can be carried out using a conventional ESPI system without a camera synchronized to the object vibration or a phase shifting system. The elaboration on the method is given and experimental results are presented. 相似文献
15.
We present the simultaneous measurement of the two in-plane displacement components by electronic speckle pattern interferometry with three object beams and without an in-line reference beam. Three interference fringe patterns, corresponding to three different sensitivity vectors, are recorded in a single interferogram and separated by means of the Fourier transform method. Then, two interference fringe patterns are selected to obtain the in-plane displacement components. 相似文献
16.
We report on the errors obtained by comparing in- and out-of-plane displacements calculated from the sensitivity matrix with all its components, and when only the component from the largest contributing of each one of the three interferometers is considered. Divergent illumination is considered in the evaluation of sensitivity vector to measure displacement vector components. This analysis is performed for a flat elastic target which is loaded in the x-direction and after in the z-direction. The technique applied is electronic speckle pattern interferometry. 相似文献
17.
A new method of using time-averaged digital speckle pattern interferometry for the quantitative measurement of vibration amplitude was developed. Signal processing techniques especially the Hilbert transformation for quantitative evaluation of the Bessel fringes obtained in time-averaged digital speckle pattern interferometry were explored. The quadrature signal after Hilbert transformation is equivalent to a 90° phase-shifted interferogram for a monotonically increasing or decreasing phase function. An algorithm was developed for Bessel fringe contrast enhancement and phase extraction. The techniques were tested numerically and experimentally. Sub-fringe quantification of the time-averaged vibration fringes is realised with the proposed method. Compared with the commonly used phase shift method which requires a minimum of two images for image processing, this method requires only one fringe pattern for data extraction. 相似文献
18.
19.
In this paper, twin-object-beam electronic speckle interferometry is used to study the longitudinal corrosion of carbon steel. The displacement expression of this technique is deduced and optical fibers are used to reduce the influence of the optical system and improve the quality of speckle pattern. Twin-object-beam electronic speckle interferometry cannot only quantitatively cipher out off-plane displacement as a result of corrosion, but also estimate the change of corrosion speed. 相似文献