Deformation measurement of conducting polythiophene thin films by an electronic speckle pattern interferometric method

The deformation measurement of electrosynthesized polythiophene (Pth) thin films is difficult because of the small thickness and high flexibility of the specimen. An electronic speckle pattern interferometry (ESPI) method is used to measure the deformation of Pth films of thicknesses in the range of 4–65 μm. Their stres-strain curve are obtained. It is found that the mechanical properties of Pth films are sensitive to the specimen thickness. The tensile strength increases with decreasing thickness of thin film from 10 μm. The influence of the electrochemical synthesis conditions on the mechanical properties of Pth films is also discussed. Project supported by the Basic-Research Foundation of Tsinghua University (JC2000057), and the Visiting Scholar Foundation of Solid Mechanical Key Lab in Tongji University of the Ministry of Education of China. Received 10 September 2001; revision received 9 November 2001.     

部分相干像面散斑技术

本文以光的部分相干性理论为指导,讨论了部分相干像面散斑(通常称为白光散斑)技术的关键.其结果可与激光像面散斑媲美.     

激光散斑干涉法测量金属复合引线热膨胀系数的实验研究

本文采用激光散斑干涉法测量微电子金属封装用金属复合引线的热膨胀系数。该方法有很高的测量精度和灵敏度,并对试件形状、尺寸和表面无特殊要求。同时利用光学方法全场测量的优点,使用已知热膨胀系数的金属材料作为标准试件,可减少温度场不均匀分布及微小变化对测试精度的影响,消除了测量光路几何参数导致的系统误差。在相对简单的实验设备下,得到较高精度金属复合引线的热膨胀系数值。该方法可广泛用于各种新材料的热膨胀系数的测定。     

一种新的数字散斑相关方法及其应用

本文提出了一种新的改进的数字散斑相关方法——十字搜索法。采用该方法将大大缩短计算时间，从而使数字散斑相关在微机上得到成功的应用。本文还从概率与统计的角度提出了新的相关系数计算公式，这个计算公式可以提高计算精度。文中还讨论了高精度测量的一些技术问题。初步实验验证表明，本文所提出的方法是一种实用的快速、高精度的位移、应变测试方法。     

用曲线大窗口平滑散斑条纹图的方法研究

提出一种计算条纹方向的简单算法,以及通过条纹方向图获得沿条纹方向的曲线窗口并对散斑条纹图进行曲线大窗口滤波的方法．实验表明此方法较好地消除了散斑条纹图的噪声,同时尽量减小了对条纹结构的损害．为从单幅散斑条纹图中应用条纹中心线法或全灰度法进一步提取相位场的后处理,奠定了良好的基础．     

散斑与数字技术

本文总结了过去十年中散斑数字技术在力学、医学、无线电电子学和天文学中的应用和进展,以及在这些领域中所发展的各种新的理论、实验技术和实验方法。     

A new interferometric method for vibration measurement by electronic holography

Electronic holography is a well-established technique used in real-time, non-contact, whole-field displacement measurements. When using the real-time, time-averaged method for vibration measurments, the quantitative interpretation of dense fringe patterns is difficult because of speckle noise. Even when speckle-reducing procedures are used, such as multiple-frame averaging or rotation of the illumination beam, the remaining speckles and decreasing visibility of higher-order Bessel fringes are serious limitations. The primary objective of this paper is to present a new realtime, interferometric method for mechanical vibration measurements and the associated quantitative interpretation. The fringe pattern obtained by this method is quasi-binary and half as dense as in the time-averaged method. The method greatly improves the overall visibility (contrast, resolution) of vibration fringe patterns without any sacrifice in the real-time capabilities. Quantitative fringe interpretation is straightforward and based on binary fringe tracking. It allows quantitative measurements in situations where the time-averaged fringe processing fails.     

离焦对散斑测量灵敏度的影响

本文分析了象差函数对光学传递函数的性态影响,指出在用白光主观散斑法测量曲面变形时,由于成象系统不能对曲面上各点同时对焦,各物点有不同程度的离焦,而造成光学传递函数对频率响应的下降,有效截止频率的降低,从而影响其测量灵敏度的提高。     

钢纤混凝土裂纹尖端应变场的实验研究

本文应用散斑干涉技术在四组含纤量分别为０，０．５％，１％，１．５％的钢纤混凝土三点弯曲裂纹试件的裂纹尖端位移场进行了测试，并换算为应变场。对钢纤混凝土开裂的基理进行了探讨；验证了最大位应变准则；并测定断裂韧度Ｊｉｃ．     

大变位时物体变形测量的相关性恢复方法

本文提出根据白光散斑图像数据模拟刚体位移复位的相关性恢复方法，以解决物体大变位情况下的变形测量问题