The digital image correlation (DIC) technique is a method of measuring the displacement and strain of the entire area of a structure by comparing surface images taken by digital cameras before and after deformation of the structure. The DIC technique is currently being spotlighted because it can overcome the weakness of conventional contact measurement methods. So far a single DIC system with one camera or two cameras has been used for most applications. However, many structures need two or more DIC systems in order to measure their deformation efficiently and precisely. For example, the stress concentration problem and the cylindrical shell buckling problem are typical applications for a multi-DIC system. This study focuses on the stress concentration problem. The paper presents a globallocal deformation measurement method with a multi-DIC system. First, a tensile test of an aluminum beam was performed and compared with the strain gage method to validate the accuracy of DIC method. Then the tensile test specimens with a hole or a notch were prepared, and one DIC system measured the local deformation near a hole or a notch and the other DIC system measured the global deformation of the specimen. The results confirmed the proposed multi-DIC technique can be applied to the stress concentration problem.

数字图像相关（DIC）技术是一种通过比较数码相机在结构变形前后拍摄的表面图像来测量结构整个区域的位移和应变的方法。DIC技术由于可以克服常规接触测量方法的缺点而受到关注。到目前为止，大多数应用程序都使用带有一台摄像机或两台摄像机的单个DIC系统。但是，许多结构需要两个或多个DIC系统才能有效且精确地测量其变形。例如，应力集中问题和圆柱壳屈曲问题是多DIC系统的典型应用。这项研究的重点是应力集中问题。本文提出了一种采用多DIC系统的全局局部变形测量方法。首先，进行了铝梁的拉伸试验，并将其与应变计方法进行比较以验证DIC方法的准确性。然后制备具有孔或缺口的拉伸试样，一个DIC系统测量孔或缺口附近的局部变形，另一个DIC系统测量试样的整体变形。结果证实了所提出的multi-DIC技术可以应用于应力集中问题。