Dataset to track concrete cracking using DIC with fixed and moving camera

Today, Digital Image Correlation (DIC) has become a standardized method to track displacements and crack-propagation of civil engineering structures in a laboratory environment. The benefit of using DIC over other standard methods is that it is contact-free and only requires a standard DSLR camera. Moreover, the displacement can be tracked over the entire image, which is a great advantage compared to the limitations of standard sensors that only measure the deformation at a specific point. In standard DIC, the displacements are directly extracted from the images. Hence, the position of the camera must be fixed during the entire test. Therefore, DIC is commonly used in a laboratory environment to measure displacement during short-term testing, e.g. testing of the structural capacity of a reinforced concrete beam. The data presented in this paper was used to verify a newly developed and innovative photogrammetric algorithm, Deformation from Motion (DfM). This algorithm overcomes the standard limitation of traditional DIC and enables high-accuracy measurements to be performed using a camera with no fixed position. As a reference, the crack propagation was on one side monitored with a LVDT and on the other side with a camera with a fixed position. During testing, a moving camera also captured imagery on both sides.

如今，数字图像相关法（Digital Image Correlation, DIC）已成为实验室环境下追踪土木工程结构位移与裂纹扩展的标准化测试方法。相较于其他常规标准测试手段，采用DIC的优势在于无需接触被测对象，且仅需一台标准数码单反相机（Digital Single-Lens Reflex Camera, DSLR）即可完成测试。此外，该方法可实现整幅图像范围内的位移追踪，相较仅能监测单点变形的标准传感器，这一特性具备显著的技术优势。在传统标准DIC流程中，位移直接从采集的图像中提取，因此整个测试过程中相机的位置必须保持固定。正因如此，DIC通常仅应用于实验室环境下的短期测试场景，例如钢筋混凝土梁的结构承载力试验。本文所呈现的数据集，被用于验证一款全新研发的创新型摄影测量算法——运动形变法（Deformation from Motion, DfM）。该算法突破了传统DIC的固有局限，可在相机位置不固定的场景下实现高精度变形测量。作为对照参照，试验过程中在试样一侧采用线性可变差动变压器（Linear Variable Differential Transformer, LVDT）监测裂纹扩展，另一侧则采用固定位置的相机进行同步监测。测试期间，一台移动相机同时对试样两侧场景完成图像采集。