Vigón Paula, Viña Jaime, Lozano Miguel, Argüelles Antonio
Department of Construction and Manufacturing Engineering, University of Oviedo, West Departmental Building No. 7, Viesques Campus, Gijón, 33203, Spain.
Department of Materials Science and Metallurgical Engineering, University of Oviedo, East Departmental Building, Viesques Campus, Gijón, 33203, Spain.
Sci Rep. 2025 Jul 29;15(1):27735. doi: 10.1038/s41598-025-12231-z.
This work analyses how environmental degradation affects the behaviour of adhesive joints in carbon-epoxy composites. These joints, made from a unidirectional carbon fibre-reinforced epoxy matrix and bonded with an epoxy-based adhesive, were tested under mode II fracture static and fatigue loading conditions. The experimental analysis was carried out using the End Notched Flexure (ENF) test method to evaluate both the fatigue initiation phase (G-N curves) and the fatigue crack growth phase (G-da/dN curves). Specimens were subjected to controlled exposure in a salt spray chamber and a climatic chamber (hygrothermal) with different exposure periods: no exposure, 1 week, 2 weeks, 4 weeks and 12 weeks. Fatigue initiation data were analysed using a probabilistic Weibull distribution model. Key findings reveal that environmental degradation significantly reduces the fatigue resistance of the adhesive joints. Under static loading, the load capacity of the adhesive joints decreased by approximately 20% after saline exposure and 25% after hygrothermal exposure. Additionally, fatigue crack growth rates were found to change depending on the type and duration of environmental exposure, underscoring the critical role of environmental conditions on joint behaviour.
这项工作分析了环境退化如何影响碳 - 环氧复合材料中粘接接头的性能。这些接头由单向碳纤维增强环氧基质制成，并用环氧基胶粘剂粘结，在II型断裂静态和疲劳加载条件下进行了测试。实验分析采用端部切口弯曲（ENF）试验方法，以评估疲劳起始阶段（G - N曲线）和疲劳裂纹扩展阶段（G - da/dN曲线）。对试样在盐雾试验箱和气候试验箱（湿热）中进行不同暴露时间的控制暴露：无暴露、1周、2周、4周和12周。使用概率威布尔分布模型分析疲劳起始数据。主要研究结果表明，环境退化显著降低了粘接接头的疲劳抗性。在静态加载下，盐雾暴露后粘接接头的承载能力下降了约20%，湿热暴露后下降了25%。此外，发现疲劳裂纹扩展速率根据环境暴露的类型和持续时间而变化，突出了环境条件对接头性能的关键作用。
