In the framework of the adhesive bonding, the assessment of interfacial properties has an essential role in determining the adhesive joints' global responses. Various surface preparations are available for each type of metallic substrate. There are plenty of tests widely used for mechanical characterisation to determine the adhesive properties and few tests to assess interfacial properties. For such a case, a specific three-point bending test can be applied to examine the interactions between adhesive and substrate. On the other hand, a direct comparison of the critical force is not always possible because of geometrical incompatibility. A practical solution for the last issue is applying a coupled stress-energy criterion (CC) since the interface properties are independent of the substrate thickness. Hence, CC and the macro-element technique were applied to determine the interfacial properties using an aluminium alloy 2024-T3 as substrate and the adhesive DGEBA/DETA™ under many preparation conditions.

As a result, the three-point bending test's overall behaviour was established in terms of interface strength (adherence), including incremental energy release rate and critical stress. Thus, this paper can be read as the first work towards the ability to predict the interface failure in the frame of three-point bending test using different geometries. In conclusion, the occurrence of an adhesive or cohesive failure and the unstable or a stable failure propagation of the bonded joints were sorted and classified as a function of interface properties.

在粘合剂粘合的框架内，界面特性的评估在确定粘合剂接头的整体响应方面具有重要作用。每种类型的金属基材都有不同的表面处理方法。有大量测试广泛用于机械表征以确定粘合性能，而很少有测试用于评估界面性能。对于这种情况，可以应用特定的三点弯曲测试来检查粘合剂和基材之间的相互作用。另一方面，由于几何不兼容，临界力的直接比较并不总是可能的。最后一个问题的实际解决方案是应用耦合应力-能量准则 (CC)，因为界面特性与基板厚度无关。因此，

因此，三点弯曲试验的整体行为是在界面强度（粘附）方面建立的，包括增量能量释放率和临界应力。因此，这篇论文可以被看作是在使用不同几何形状的三点弯曲试验框架中预测界面失效能力的第一项工作。总之，粘合或内聚破坏的发生以及粘合接头的不稳定或稳定破坏传播被分类并归类为界面特性的函数。