Abstract Though several studies have tried to explain and model the effect of thickness on crack growth behavior, this remains a controversial topic. The present paper proposes an approach to model the fatigue crack growth with different thicknesses, which requires crack growth experimental data with different specimen thicknesses and out-of-plane constraint distribution relations for CT specimens. Empirical formula, for the distributions of two types of constraint factors Tz and T33, were fitted according to the FEA results. The stress state variation induced by the thickness was quantified using the formulas; then, the crack driving force was modified to establish the novel crack growth model. The predictions using this model largely agree with the experimental data. So, the newly developed model was verified. This paper proposes a new perspective on quantifying the effect of crack thickness, and provides an alternative to the traditional method of modeling the crack growth behavior.

中文翻译：

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对贯穿厚度裂纹的疲劳裂纹扩展建模：一种考虑厚度效应的基于平面外约束的方法

摘要 尽管一些研究试图解释和模拟厚度对裂纹扩展行为的影响，但这仍然是一个有争议的话题。本文提出了一种模拟不同厚度疲劳裂纹扩展的方法，这需要不同试样厚度的裂纹扩展实验数据和CT试样的平面外约束分布关系。根据有限元分析结果拟合了两类约束因子Tz和T33分布的经验公式。由厚度引起的应力状态变化使用公式量化；然后，修改裂纹驱动力以建立新的裂纹扩展模型。使用该模型的预测与实验数据基本一致。因此，新开发的模型得到了验证。