Shao Xinxing, Qu Jingye, Chen Wenwu
Department of Engineering Mechanics, School of Civil Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2023 Mar 29;16(7):2726. doi: 10.3390/ma16072726.
Owing to the advantages of cost-effectiveness, compactness, and the avoidance of complicated camera synchronization, single-camera three-dimensional (3D) digital image correlation (DIC) techniques have gained increasing attention for deformation measurement of materials and structures. In the traditional single-camera 3D-DIC system, the left and right view images can be recorded by a single camera using diffraction grating, a bi-prism, or a set of planar mirrors. To further improve the measurement accuracy of single-camera 3D-DIC, this paper introduces a single-camera four-view imaging technique by installing a pyramidal prism in front of the camera. The 3D reconstruction of the measured points before and after deformation is realized with eight governing equations induced by four views, and the strong geometric constraints of four views can help to improve the measurement accuracy. A static experiment, a rigid body translation experiment, and a four-point bending experiment show that the proposed single-camera 3D-DIC method can achieve higher measurement accuracy than the dual-view single-camera 3D-DIC techniques and that the single-camera 3D-DIC method has advantages in reducing both random error and systematic error.
由于具有成本效益、紧凑性以及避免复杂相机同步等优点，单相机三维（3D）数字图像相关（DIC）技术在材料和结构变形测量方面越来越受到关注。在传统的单相机3D-DIC系统中，左视图和右视图图像可由单相机使用衍射光栅、双棱镜或一组平面镜进行记录。为了进一步提高单相机3D-DIC的测量精度，本文通过在相机前安装一个棱锥棱镜引入了一种单相机四视图成像技术。利用由四个视图导出的八个控制方程实现变形前后测量点的三维重建，并且四个视图的强几何约束有助于提高测量精度。静态实验、刚体平移实验和四点弯曲实验表明，所提出的单相机3D-DIC方法比双视图单相机3D-DIC技术能实现更高的测量精度，并且单相机3D-DIC方法在降低随机误差和系统误差方面具有优势。
