The present work addresses two key issues relating to the study of rate effects in adhesively bonded joints. Firstly, the accurate determination of the crack tip strain rate and secondly the accurate determination of cohesive zone length. The rate-dependent fracture behaviour of adhesive joints bonded with either a toughened epoxy or a ductile polyurethane adhesive was investigated under mode I loading rates ranging from 0.1 mm/min to 1.0 m/s with digital image correlation (DIC) analysis. The traction-separation laws (TSLs) were determined by measuring the J-integral values and the crack tip opening displacements simultaneously. An analytical method is proposed to correlate the crack tip opening velocity with the external loading rate. The lengths of the cohesive zones were measured, and the values were compared with results obtained from thickness-independent and -dependent models. The cohesive properties of the two adhesives exhibited very different rate dependences. The analytical tool developed using the DIC approach successfully determines the strain rates for the TSLs investigated.

目前的工作解决了与研究胶接接头的速率效应有关的两个关键问题。首先，精确确定裂纹尖端应变率，其次，精确确定内聚区长度。使用数字图像相关性（DIC）分析，研究了在模式I加载速率为0.1 mm / min至1.0 m / s的情况下，与增韧环氧树脂或韧性聚氨酯粘合剂粘合的粘合剂接头的速率依赖性断裂行为。牵引力分离定律（TSLs）通过测量J来确定-积分值和裂纹尖端的开口位移同时发生。提出了一种分析方法，将裂纹尖端的打开速度与外部加载速率相关联。测量了粘结区域的长度，并将其与从厚度无关和依赖性模型获得的结果进行了比较。两种粘合剂的内聚性能表现出非常不同的速率依赖性。使用DIC方法开发的分析工具成功确定了所研究的TSL的应变率。