Abstract In this study, different single-lap hybrid joints are used to analyse the effects of the stiffness of the adherends and the adhesive on the failure mechanism. The hybrid joints include a combination of (a) different adherends: aluminium (6082 T6) and PolyPhtalamide (PPA) reinforced with 50% of glass fibre (grade HTV-5H1 from Grivory) and (b) different adhesives: epoxy-based adhesive (Loctite EA 9497) and silane-modified polymer-based adhesive (Teroson MS 9399). Six different single-lap joints are fabricated and analysed. The cohesive parameters of different adhesives against different adherends are determined respectively using single-mode coupons and validated with finite element modelling. Single-lap shear tests are conducted to understand different fracture mechanisms of the joints. Finite element (FE) models using the Cohesive Zone Method (CZM) are developed to simulate the failure of the joints and validated by the testing results. Different failure processes obtained from different hybrid joints combinations are discussed further by analysing the stress distributions along the interfaces of the joints. Finally, the relationship between the stiffness of the constituents of a hybrid adhesive joint and its failure mechanism is summarised. The load vs displacement behaviour of the single-lap joints demonstrate that the stiffness of adherends affects the maximum failure load of the joints with rigid adhesive (epoxy). However, the joint with flexible adhesive (polyurethane) is not sensitive to the stiffness of the adherends. In addition, higher shear stress distribution occurs in the interface adjacent to the adherend with lower stiffness, leading to the failure initiation at the PPA side regardless of adhesive types.

中文翻译：

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混合粘合剂粘合接头的断裂机制：成分刚度的影响

摘要 本研究采用不同的单搭接混合接头，分析被粘物刚度和胶粘剂对破坏机理的影响。混合接头包括 (a) 不同被粘物的组合：铝 (6082 T6) 和用 50% 玻璃纤维增​​强的聚邻苯二甲酰胺 (PPA)（来自 Grivory 的 HTV-5H1 级）和 (b) 不同粘合剂：环氧基粘合剂（ Loctite EA 9497）和硅烷改性聚合物基粘合剂（Teroson MS 9399）。制造和分析了六个不同的单搭接接头。不同粘合剂对不同被粘物的内聚参数分别使用单模试样确定，并通过有限元建模进行验证。进行单搭接剪切试验以了解接头的不同断裂机制。开发了使用内聚区法 (CZM) 的有限元 (FE) 模型来模拟接头的失效并通过测试结果进行验证。通过分析沿接头界面的应力分布，进一步讨论了从不同混合接头组合获得的不同失效过程。最后，总结了混合粘合剂接头组成部分的刚度与其失效机制之间的关系。单搭接接头的载荷与位移行为表明，被粘物的刚度影响刚性粘合剂（环氧树脂）接头的最大失效载荷。然而，具有柔性粘合剂（聚氨酯）的接头对被粘物的刚度不敏感。此外，