The translaminar fracture toughness and its dependence on the environmental condition are key considerations in designing aerospace-grade composites with a high damage tolerance to severe service conditions in terms of temperature and moisture. The present work characterises and models the hygrothermal effects on the translaminar fracture toughness of an interlaminar toughened aerospace carbon/epoxy composite under six environmental conditions: −55 °C, 23 °C, and 90 °C, for both ‘dry’ (i.e. moisture free) and ‘wet’ (fully moisture-saturated) specimens. Cross-ply compact-tension experiments show that the translaminar fracture toughness increases with the rise of temperature for both dry and wet conditions with the latter exhibiting a much greater increase. A model to predict the effect of moisture and temperature on the translaminar fracture toughness is here proposed and developed. This approach yields good agreement with experimental results, and it allows an improved understanding of the complex synergistic effects of interfacial properties on the overall translaminar toughening mechanisms.

跨层断裂韧性及其对环境条件的依赖性是设计航空级复合材料的关键考虑因素，该复合材料对温度和湿度等严苛的使用条件具有高损伤容限。目前的工作表征和模拟了在六种环境条件下湿热对层间增韧航空碳/环氧树脂复合材料的跨层断裂韧性的影响：-55 °C、23 °C 和 90 °C，对于“干燥”（即水分）游离）和“湿”（完全水分饱和）标本。交叉层密实张力实验表明，在干燥和潮湿条件下，跨层断裂韧性随着温度的升高而增加，后者表现出更大的增加。这里提出并开发了一种预测水分和温度对跨层断裂韧性影响的模型。这种方法与实验结果非常吻合，并且可以更好地理解界面特性对整体跨层增韧机制的复杂协同效应。