Abstract The correlation between nanoscale interface debonding and crack energy release rate for modes I, II, and I/II for extended exposure to hygrothermal conditions in polymer matrix composites (PMCs) needs to be understood. In this study, the effects on PMCs for two years of exposure, to a heat of 60 °C and relative humidity of 90%, were investigated. The interphase properties were studied using PF QNM. During hygrothermal treatment, the interphase region's thickness around the crack tip increases, and the morphology of the interphase changes. Nanoscale debonding of the fiber and matrix in artificially aged samples is a mix of cohesive and adhesive failure. Degradation at the nanoscale interphase and the macroscale crack initiation toughness slows after one year of aging. Interface debonding and nanoscale cracks cause intralaminar cracks, fiber bridging, and an increase in crack energy. Toughness in mode I fracture was increased in the artificially aged samples.

中文翻译：

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聚合物碳复合材料中纳米级界面脱粘和多模断裂与长期湿热效应的相关性

摘要 需要了解在聚合物基复合材料 (PMC) 中长时间暴露于湿热条件下的模式 I、II 和 I/II 的纳米级界面脱粘与裂纹能量释放率之间的相关性。在这项研究中，研究了在 60 °C 的高温和 90% 的相对湿度下暴露两年对 PMC 的影响。使用 PF QNM 研究界面特性。在湿热处理过程中，裂纹尖端附近的界面区厚度增加，界面相的形貌发生变化。人工老化样品中纤维和基质的纳米级脱粘是内聚和粘合失效的混合体。时效一年后，纳米级界面的降解和宏观裂纹萌生韧性减慢。界面脱粘和纳米级裂纹导致层内裂纹，纤维桥接和裂纹能增加。在人工老化的样品中，I 型断裂的韧性增加。