Measurements of fatigue crack propagation are crucial for fatigue tests. Nowadays, fatigue tests still necessitate experimenters to manually observe and document the propagation of fatigue cracks, a process that proves to be extremely time-consuming and labor-intensive. This study introduces a novel approach to fatigue crack measurement by employing the decorrelated digital image correlation (DIC) technique, which stands in contrast to the conventional DIC method. The proposed method utilizes decorrelation field to extract crack propagation path. The proposed method enables the automated measurement of fatigue crack parameters such as width, length, and morphology. Both numerical simulations and physical model experiments were conducted to validate the effectiveness of the proposed method. The numerical experiments demonstrate that the method achieves sub-pixel level accuracy in measuring crack width, length, and morphology. The results from physical experiment further affirm the feasibility of the method for practical application.

中文翻译：

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基于去相关数字图像相关的疲劳裂纹扩展自动测量方法

疲劳裂纹扩展的测量对于疲劳试验至关重要。如今，疲劳测试仍然需要实验人员手动观察和记录疲劳裂纹的扩展，这一过程被证明是极其耗时和劳动密集型的。本研究介绍了一种采用解相关数字图像相关（DIC）技术来测量疲劳裂纹的新方法，该方法与传统的 DIC 方法形成鲜明对比。该方法利用去相关场来提取裂纹扩展路径。该方法能够自动测量疲劳裂纹参数，如宽度、长度和形态。通过数值模拟和物理模型实验验证了该方法的有效性。数值实验表明，该方法在测量裂纹宽度、长度和形貌方面达到了亚像素级精度。物理实验结果进一步证实了该方法实际应用的可行性。