Digital image correlation (DIC) has become one of the most popular methods for deformation characterization in experimental mechanics. DIC is based on optical images taken during experimentation and post-test image processing. Its advantages include the capability to capture full-field deformation in a non-contact manner, the robustness in characterizing excessive deformation induced by events such as yielding and cracking, and the versatility to integrate optical cameras with a variety of open-source and commercial codes. In this paper, we developed a new paradigm of DIC analysis by integrating camera control into the DIC process flow. The essential idea is to dynamically increase the camera imaging frame rate with excessive deformation or deformation rate, while maintaining a relatively low imaging frame rate with small and slow deformation. We refer to this new DIC paradigm as in-situ on-demand (ISOD) DIC. ISOD DIC enables real-time deformation analysis, visualization, and closed-loop camera control. ISOD DIC has captured approximately 178% more images than conventional DIC for samples undergoing crack growth due to its dynamically adjusted frame rate, with the potential to significantly enhance data richness for damage inspection without consuming excessive storage space and analysis time, thereby benefiting the characterization of intrinsic constitutive behaviors and damage mechanisms

翻译：数字图像相关（DIC）已成为实验力学中最为流行的变形表征方法之一。DIC基于实验过程中采集的光学图像以及试验后的图像处理。其优势包括能够以非接触方式捕获全场变形、在表征由屈服和开裂等事件引起的过度变形方面具有鲁棒性，以及能够将光学相机与多种开源和商业代码灵活集成。本文通过将相机控制集成到DIC处理流程中，发展了一种新的DIC分析范式。其核心思想是：在变形剧烈或变形速率较高时动态提高相机成像帧率，而在变形小而缓慢时保持相对较低的成像帧率。我们将这一新的DIC范式称为原位按需（ISOD）DIC。ISOD DIC能够实现实时变形分析、可视化以及闭环相机控制。对于经历裂纹扩展的试样，由于其动态调整的帧率，ISOD DIC捕获的图像数量较传统DIC增加了约178%，有望在不消耗过多存储空间和分析时间的前提下，显著提升损伤检测的数据丰富度，从而有利于表征材料本构行为与损伤机制。