ABSTRACT

To investigate the mode I fracture properties of adhesively bonded joints after water ageing, the authors reduced here the width of Tapered Double Cantilever Beam (TDCB) specimens to 5 mm (compared to typical values encountered in literature at 10 mm). This was decided in order to reach the desired water absorption levels within a reasonable time. However, this operation was found to increase the impact of the edge effects on the fracture results, which were illustrated by finite element simulations. Hence, to improve consistency and stability of crack propagation, special beaks were added on the surfaces of the substrates close to the adhesive layer, based on previous solutions implemented for Arcan specimens. The results showed that the fracture energy decreased very rapidly to about half of its initial (unaged) value, and remained almost constant for all water ageing times that were examined in this work (4, 8, and 12 months).

摘要

为了研究水老化后粘合接头的 I 型断裂特性，作者将锥形双悬臂梁 (TDCB) 试样的宽度减小到 5 毫米（与文献中在 10 毫米处遇到的典型值相比）。这是为了在合理的时间内达到所需的吸水率而决定的。然而，发现这种操作会增加边缘效应对断裂结果的影响，这可以通过有限元模拟来说明。因此，为了提高裂纹扩展的一致性和稳定性，基于先前为 Arcan 试样实施的解决方案，在靠近粘合剂层的基材表面上添加了特殊的喙。结果表明，断裂能非常迅速地下降到其初始（未老化）值的一半左右，