Abstract A previous study indicated that the normalized fracture controlling parameter (strain energy release rate G normalized by fatigue delamination resistance Gcf) in the Paris-type law has advantages of lower exponents and data scatter to evaluate the fatigue delamination growth (FDG) behavior. To accurately determine the critical Gcf, which characterizes the real changing resistance against delamination growth, a novel model is proposed from a viewpoint of energy. This model also allows the judgement on the numerical equivalence between the Gcf and fracture toughness Gc in a simple way. Well-designed delamination tests under mode I loading were carried out to validate the model. Significant R-curve effects on the FDG behavior due to fiber bridging and the bridging difference between static and fatigue delamination at the same delamination length were observed. The calculated result of Gcf has a really good agreement with that obtained by the compliance method, which indicates that fatigue delamination resistance can be accurately determined by using the present model.

中文翻译：

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从能量角度确定复合材料层合板疲劳分层抗力的新模型

摘要 前人的研究表明，巴黎型定律中的归一化断裂控制参数（应变能释放率G由疲劳分层阻力Gcf归一化）在评估疲劳分层增长（FDG）行为时具有指数较低和数据分散的优点。为了准确确定临界 Gcf，它表征了对分层增长的真实变化阻力，从能量的角度提出了一种新模型。该模型还允许以简单的方式判断 Gcf 和断裂韧性 Gc 之间的数值等价性。在模式 I 加载下进行了精心设计的分层测试以验证模型。观察到由于纤维桥接以及相同分层长度下静态和疲劳分层之间的桥接差异对 FDG 行为的显着 R 曲线影响。Gcf 的计算结果与柔量法得到的结果具有很好的一致性，表明使用该模型可以准确地确定抗疲劳分层性能。