三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,...三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,三维数字图像相关法具有测量精度高,可准确测量物体表面的三维形貌和变形等优点。本文介绍了三维数字图像相关法的基本原理、关键技术和精度分析等,并结合水泥基材料的特点,讨论了三维数字图像相关法在水泥基材料变形研究中的应用。展开更多
Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of di...Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.展开更多
文摘三维数字图像相关法(three-dimensional digital image correlation,3D-DIC)又称三维数字散斑相关法(threedimensional digital speckle correlation method,3D-DSCM),是一种新型的非接触式全场光学测量方法。与比长仪等传统方法相比,三维数字图像相关法具有测量精度高,可准确测量物体表面的三维形貌和变形等优点。本文介绍了三维数字图像相关法的基本原理、关键技术和精度分析等,并结合水泥基材料的特点,讨论了三维数字图像相关法在水泥基材料变形研究中的应用。
基金supported by the National Natural Science Foundation of China(Grant Nos.11332010,51271174,11372300,11127201,11472266&11428206)
文摘Three dimensional-digital image correlation （3D-DIC） is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation （DIC） has been thoroughly studied theoretically and numerically, verification experiments have seldom been performed, especially fbr complex surfaces with a small field of view （FOV）. In this work, the shape of a 1-yuan coin was measured using 3D-DIC; the shape was complex due to the presence of many fine details, and the FOV was relatively small because the coin diameter was only 25 mm. During the experiment, a novel strategy for speckle production was developed： white paint was simply sprayed onto the surface. Black paint was not used; instead, taking advantage of the reflective nature of the coin surface, polarized light and a Polaroid filter were introduced, and the polarization direction was carefully adjusted, ensuring that the spray pattern was extremely thin and that high-quality speckle images with significant contrast were captured. The three-dimensional coin shape was also successfully determined for comparison using a stylus profiler. The results demonstrate that 3D-DIC provides high precision in shape measurement even for complex surfaces with small FOV. The precision of 3D-DIC can reach 1/7000 of the field of view, corresponding to about 6 ~tm in this experiment.
