三维电子散斑干涉全场高精度应变同步测试系统研制

项目名称： 三维电子散斑干涉全场高精度应变同步测试系统研制

项目编号： No.11472081

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 杨福俊

作者单位： 东南大学

项目金额： 120万元

中文摘要： 目前数字图像相关方法是测量三维全场应变的主要手段之一，但其应变测试精度受试件表面散斑质量优劣的影响较大,且灵敏度一般在100微应变左右。本项目拟采用独立多波长激光散斑干涉方法、同步相移控制、三色CCD相机采集及数字图像处理技术，发展新的能够直接测量材料或结构三维应变的系统。本课题通过不同颜色激光散斑干涉同时调制不同方向的变形，由彩色相机获取同步相移散斑干涉图像，应用时间序列图像并结合多线程后台图像快速处理技术实现灵敏度不低于5微应变、20-2000微应变量级的静态三维全场应变测量,该测量系统无需光学剪切硬件实现材料或结构的静态变形与应变信息的同步检测；同时，拟研制的测试装置除了用于常规固体材料外，还适合于凝胶等软性材料的变形测量，这将为研究凝胶类材料在电场、磁场等载荷作用下的力学性能研究提供可靠与精确的测试平台。

中文关键词： 全场应变测量；散斑干涉技术；多波长；同步相移方法；数字图像处理

英文摘要： Digital image correlation method (DICM) is one of main techniques for three-dimensional deformation measurement. However, its precision is limited by speckles' quality of the testing object, and its sensitivity is no more than 100 micro-strain for strain analysis. The proposed project will develop a new device for simultaneously measuring three-dimensional deformation of a deformed object in electric speckle pattern interferometry (ESPI). In the proposed method, lasers of three wavelengths are used to simultaneously illuminate the object along various directions so that a unique wavelength is used for a given direction, and three PZT drivers are used for generating 4-step phase-shifting. The speckle patterns with phase-shifting formed by multiple reference-object beam pairs of different wavelengths are recorded by a 3-color CCD camera with red, green and blue channels. Each channel stores the speckle patterns related to the corresponding wavelength and hence for the specific direction. The phase of interference fringes is obtained for each wavelength by digital processing of the recorded speckle patterns before and after deformation. Time sequence phase method and multiple-thread image processing technique will be used for demodulating fringes' phase and calculating strain. The strain sensitivity of the measurement system in developing is no less than 5 micro-strain, and the measuring range of strain is from 20 to 2000 micro-strain. The measurement system in developing can simultaneously obtain the results of displacement and strain without using shear components. The system in developing can be used in testing mechanical properties of materials, components and structures. It will also provide a good testing platform for characterization of dielectric elastomers deformation responding to electric or magnetic loading.

英文关键词： full-field strain measurement;Electric Speckle Pattern Interferometry;multi-wavelength;synchro-phase-shifting;digital image processing