Abstract In-situ X-ray tomography is an effective means for the acquisition of time-resolved 3D images of fiber reinforced composites during mechanical loading and deformation. However, the manual comparison of corresponding in-situ X-ray images at successive loading instances to detect damage and its propagation is a time-consuming process. To improve the detection of damage using in-situ X-ray tomography, digital volume correlation (DVC), a full field 3D-strain technique that determines relative deformation between consecutive image volumes, was used. Specifically, regions of high strain were isolated from the heterogeneous strain computed from DVC within the microstructure and compared to manually detected damage. In this study, 59 out of 63 manually detected damage events, which included fiber breakage, micro-void nucleation, and fiber debonding, were within the search spaces of high strains beyond the 60th percentile threshold computed by DVC. Results of this study demonstrate the use of DVC as a tool to confine volumes of potential damage sites within the in-situ X-ray tomograms of composites to improve the efficiency of incipient damage detection.

中文翻译：

---

通过原位 X 射线断层扫描和数字体积相关检测短纤维复合材料的损伤起始

摘要 原位 X 射线断层扫描是获取纤维增强复合材料在机械加载和变形过程中时间分辨 3D 图像的有效手段。然而，在连续加载实例中手动比较相应的原位 X 射线图像以检测损坏及其传播是一个耗时的过程。为了改进使用原位 X 射线断层扫描的损伤检测，使用了数字体积相关 (DVC)，这是一种全场 3D 应变技术，可确定连续图像体积之间的相对变形。具体而言，高应变区域与从微观结构内的 DVC 计算的异质应变中分离出来，并与手动检测到的损伤进行比较。在这项研究中，63 个手动检测到的损坏事件中有 59 个，其中包括纤维断裂、微孔成核、和纤维脱粘，在超过 DVC 计算的第 60 个百分位数阈值的高应变搜索空间内。这项研究的结果表明，使用 DVC 作为一种工具来限制复合材料的原位 X 射线断层扫描中潜在损伤部位的体积，以提高早期损伤检测的效率。