Abstract The resistance to fracture of a bonded joint is usually evaluated through the experimental characterisation of its fracture toughness. Different test procedures and data reduction methods are available in the literature, such as the ISO-25217 test standard. The need for crack length measurement has led to inaccurate results when large adhesive thicknesses or flexible adhesives were studied. Advanced test protocols based on the insertion of a wedge, such as the Wedge Test (WT) in ASTM D3762 or the Wedge-Driven Test (WDT), simplify the test procedure, but most such procedures do not allow for the measurement of fracture toughness. Further, experimental results are scarce in the literature, especially when dealing with bonded joints and considerable thicknesses. In the present work, an advanced data reduction method based on the WDT is presented: The Wedge-Driven Test Plus (WDT+). The fracture toughness of specimens made by bonding two aluminium adherends with a rigid and a flexible adhesive was measured, and the effect of wedge thickness and test speed at low displacement rates on the test results was analysed. The results were compared with static tests performed in a double cantilever beam (DCB) following ISO-25217. It has been demonstrated that the proposed data reduction method is less sensitive to test speed and enables different adhesive types, and bondline thickness and wedge thickness configurations, thereby improving the WDT available in the literature.

中文翻译：

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使用先进的楔驱动测试对刚性和柔性粘合接头进行 I 型断裂表征

摘要 粘结接头的抗断裂性通常通过其断裂韧性的实验表征来评价。文献中提供了不同的测试程序和数据简化方法，例如 ISO-25217 测试标准。在研究大粘合剂厚度或柔性粘合剂时，需要测量裂纹长度导致结果不准确。基于楔块插入的高级测试协议，例如 ASTM D3762 中的楔块测试 (WT) 或楔块驱动测试 (WDT)，简化了测试程序，但大多数此类程序不允许测量断裂韧性. 此外，文献中的实验结果很少，特别是在处理粘合接头和相当大的厚度时。在目前的工作中，提出了一种基于 WDT 的高级数据简化方法：楔形驱动测试增强版 (WDT+)。测量了用刚性和柔性粘合剂将两个铝被粘物粘合制成的试样的断裂韧性，并分析了低位移速率下楔块厚度和试验速度对试验结果的影响。结果与遵循 ISO-25217 在双悬臂梁 (DCB) 中执行的静态测试进行了比较。已经证明，所提出的数据缩减方法对测试速度不太敏感，并且可以实现不同的粘合剂类型、粘合层厚度和楔形厚度配置，从而改进了文献中可用的 WDT。分析了低位移率下楔块厚度和试验速度对试验结果的影响。结果与遵循 ISO-25217 在双悬臂梁 (DCB) 中执行的静态测试进行了比较。已经证明，所提出的数据缩减方法对测试速度不太敏感，并且可以实现不同的粘合剂类型、粘合层厚度和楔形厚度配置，从而改进了文献中可用的 WDT。分析了低位移率下楔块厚度和试验速度对试验结果的影响。结果与遵循 ISO-25217 在双悬臂梁 (DCB) 中执行的静态测试进行了比较。已经证明，所提出的数据缩减方法对测试速度不太敏感，并且可以实现不同的粘合剂类型、粘合层厚度和楔形厚度配置，从而改进了文献中可用的 WDT。