基于图像处理技术的数字散斑照相

提出一种新的数字散斑照相计量方法,该方法研究将ＣＣＤ和计算机相结合,在自然光照下了对被测量物体照相,通过一种快的图像处理,直接提取物体变形信息。突破光测的激光照明及傅里叶变换模式,实现光测量技术真正自动化。     

旋转孔径散斑照相逐点分析法

本文提出了旋转孔径散斑照相的逐点分析法,其杨氏花纹一般来说不是等距离的直条纹,而是与位移的动态过程相联系的曲线条纹.本文解释了这种条纹的意义,给出了理论分析和实验证明.     

利用散斑照相检测微小位移的实时方法

以CCD作为散斑和杨氏条纹记录设备,以与分屏器相连的电寻址空间光调制器作为滤波器,以计算机作为图像合成、条纹分辨及数据运算处理中心,并同时控制和协调CCD及空间光调制器等设备,实现了利用散斑照相实时、自动测定微小位移的过程.实验结果表明,此种方法获得的测量结果误差较小,具有一定的使用价值.     

偏振孔径散斑照相法

本文讨论了偏振片在散斑照相多孔法中的作用,提出了一种新的散斑照相孔径——偏振四孔。     

动态白光散斑法的灵敏度及其提高

本文用非相干成象系统频谱分析的概念,分析了动态白光散斑法的灵敏度问题。提出了提高灵敏度的方法,使之不仅能测量大的动态变形,而且也能测量小的动态变形,如果用光弹性材料作试件,能同时得到动态等差线,进行主应力分离。     

孔径径向扫描散斑照相法

本文提出了一种新的散斑照相法——孔径径向扫描散斑照相法,以及初步的实验结果.该方法的优点是能在一张散斑图上记录物体动态变形的全过程,在全场滤波分析时,能以等值条纹的形式给出任一瞬时物体在x轴、y轴和45°方向上的变形信息.     

孔径旋转频闪散斑照相法测量物体的固有频率

提出了一种测量物体固有频率的新方法－－孔径旋转频闪散斑照相法。该方法能方便地测量振动物体的固有频率，具有精度高、全场显示、条纹可见度好等优点，给出了理论分析和实验结果。     

散斑计量技术—走向工程实用化的技术

散斑计量技术是在现代高科技成果如激光技术、视频技术、电子技术、信息与图像处理技术、计算机技术、佤息、精密测试技术等基础上发展起来的有效工程检测技术，它具有全场、无损、灵敏、实用的优点，因而得到了迅速发展和广泛的应用，散斑计量技术的最终目的是走向工程实用化，实现现场在线测量，随着它的发展，必然会在科学研究和工程实际中发挥重大的作用。     

旋转孔径白光散斑照相法的研究

本文报道利用旋转孔径法进行白光散斑照相,研测动态问题.其不仅具有旋转孔径激光散斑照相的优点,而且最突出的优点是能走出实验室,到现场进行动态测量研究.     

电子散斑测振技术进展

综述了电子散斑在振动测量中的发展和应用,对电子散斑测振的各种方法进行评价。     

测量物体位移的数字白光散斑照相术

给出了一测量物体刚体位移的数字白光散斑照相术。数字傅里叶变换从双曝光字白光散斑图用来产生杨氏条纹。该杨氏条纹能够用数字傅里叶变换结合条纹重构进行自动分析。此外，给出一种条纹质量增强的方法。     

Digital Photography in Measuring the Inclination of the Object Surface with Formation of a Speckle Structure

Optical schemes for measuring surface inclination due to shift or deformation are considered. Speckle-interferometry methods are used. The distinguished features of these schemes are connected with using a digital photocamera and a forming speckle structure in nonmonochromatic light. Several technical solutions are proposed making it possibile to measure inclination with an accuracy up to tenths of degree using standard cheap equipment. To form the speckle structure, the pattern of a random binary structure with unit size of several millimeters is used in the base fixed plane. The digital camera was placed in the analyzed plane and turned together with the plane. It registered a reduced image of the pattern. The registration was done for two positions of the surface, the pattern being illuminated by the camera flash lamp. Measuring the width and orientation of the interference fringes formed for the two speckle structures allows one to determine the inclination and orientation of the rotation axis.     

数字散斑法在局域剪切带三维变形研究中的应用

在适当的温度、应变率和预变形下,合金材料的拉伸试验中,将会出现伴随应力锯齿形跌落的雪崩式剪切变形带,即波特文-勒夏特利埃(Portevin-Le Chatelier,PLC)效应。利用高速数字摄像系统(分辨力1000 frames/s)并结合数字散斑干涉法(Digital speckle pattern interferometry,DSPI)和数字散斑相关法设计了一套光学变形测量系统,实现了拉伸试验中对试件表面三维变形的实时、精确测量。利用该光学系统对铝铜合金试件在拉伸试验中产生的跳跃传播的局域剪切带瞬态成核过程进行捕捉。通过结合数字散斑相关法得到的面内变形定量结果和数字散斑干涉法得到的表现离面变形的条纹图,再现了剪切变形带成核和传播瞬间的三维变形过程。     

用高速显微摄影技术测量神龙一号上回喷靶材速度

用高速显微摄影技术对强流脉冲电子束轰击钽金属靶的过程进行了研究,获得了“神龙一号”加速器上靶材回喷过程的实验图像.实验表明,钽金属靶在强流脉冲电子束的作用下,有强烈的热释光现象产生,靶材的回喷粒子的轴向速度可达4.7 mm/μs.     

Digital Photography in Measurements of Shifts of Object Surfaces with Formation of the Speckle Structure In White Light

We describe and analyze the experimental realization of a speckle interferometry scheme designed for measurement of the value of the shift of the object surface along the surface itself. In contrast to classical speckle interferometric schemes, we use a specially formed two-dimensional pattern of the random binary structure as a speckle structure. The pattern being illuminated by the white light is photographed with the use of a digital camera. Further processing of the information related to the Fourier transformation of the pictures registered and determination of the obtained fringe structure period is carried out in a PC.     

Measurement of Stress Intensity Factors of a Mixed-Mode Interface Crack by a Speckle Photography

The image-processing system based on a two-dimensional Fourier transform is presented for the analysis of Young’s fringes pattern created from a double-exposure speckle photograph. The fringe spacing and orientation are determined using only one Young’s fringes pattern without any other diffraction halo patterns. The stress-intensity factors of a mixed-mode interface crack were measured by speckle photography. A compact normal and shear specimen with an interface crack was employed. This specimen enables us to carry out the experiment under various kinds of mixed-mode loading. A steel and an epoxy resin were used as dissimilar materials. The displacement along the crack lines at the free surface was measured by speckle photography. The K₁ and K₁₁ values were determined by a least squares method using displacement data along the crack lines. Three-dimensional finite element analysis was carried out on the same specimen. An accuracy of stress intensity factors obtained by the speckle photography was discussed by comparison of results obtained by the finite element analysis.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27–29, Saitama, Japan.