In this study, the crack lengths in adhesively bonded double cantilever beam (DCB) test specimens have been determined using the digital image correlation technique in combination with an elastic foundation model. This method facilitates the continuous measurement of the crack length and offers significant advantages over conventional visual observation including improved accuracy and the potential for automation. This method has been applied to three joints bonded with different structural adhesives, and fracture energy G_c values calculated with the effective crack lengths determined by this method have been shown to be accurate by comparison to J_c values. Finally, a new method is proposed to correct the crack lengths that are visually measured and the G_c values determined using the standard analysis. This scheme is shown to improve the accuracy of the G_c values appreciably.

在这项研究中，使用数字图像相关技术结合弹性地基模型确定了胶粘双悬臂梁 (DCB) 试样中的裂纹长度。这种方法有助于裂纹长度的连续测量，与传统的目视观察相比具有显着优势，包括提高精度和自动化潜力。该方法已应用于用不同结构粘合剂粘合的三个接头，并且与J _c值相比，用该方法确定的有效裂纹长度计算的断裂能G _c值已被证明是准确的。最后，提出了一种新的方法来修正目视测量的裂纹长度和裂纹长度。G _c值使用标准分析确定。该方案被证明可以显着提高G _c值的准确性。