Abstract The strength durability of adhesively bonded joints under combined mechanical and hygrothermal environments is crucial for their industrial application. In this study, the strength durability of adhesively bonded aluminium-lithium alloy joints under combined hygrothermal-mechanical conditions was investigated, three loading regimes were applied to the joints and four different hygrothermal conditions were selected. The strength degradation, failure modes, fracture morphology, and adhesive characteristics after exposure were analyzed. The results indicated that hot-humid conditions are the main causes of strength degradation compared to applied loading, however, sustained loading accelerates the rate of degradation, which is more pronounced as the temperature, humidity, loading levels, and exposure cycles increase, especially for the joints to which combined loading is applied. The joint strength degraded by 15.9% without loading application, while it reduced by 19.7%, 19.0%, and 21.8%, respectively, for tensile, bending, and combined sustained loading under temperature cycling from -40 °C to 80 °C and humidity cycling from 30% to 95%.

中文翻译：

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湿热-机械暴露对胶接接头残余强度的影响

摘要 粘接接头在机械和湿热环境下的强度耐久性对其工业应用至关重要。在这项研究中，研究了在湿热-机械组合条件下粘接铝锂合金接头的强度耐久性，对接头施加了三种加载方式，并选择了四种不同的湿热条件。分析了暴露后的强度退化、失效模式、断裂形态和粘合特性。结果表明，与施加的载荷相比，湿热条件是强度下降的主要原因，然而，持续载荷加速了退化的速度，随着温度、湿度、载荷水平和暴露周期的增加，这种情况更加明显，尤其适用于施加联合载荷的接头。在-40°C 至 80°C 的温度循环和湿度下，接头强度在不施加载荷的情况下降低了 15.9%，而在拉伸、弯曲和组合持续载荷下，接头强度分别降低了 19.7%、19.0% 和 21.8%循环从 30% 到 95%。