Abstract To predict the leakage of composite fuel tanks due to matrix cracks, this paper proposes novel simulation schemes: (1) A semi-quantitative leak rate estimation method is developed based on the crack intersection area; (2) The semi-analytical damaged constitutive model is obtained by a small amount of micro-mechanical finite element analysis (FEA); (3) The mixed mode crack density is estimated by using the FEA of laminates, which involves the progressive damaged properties; (4) The crack intersecting area is estimated based on the crack density and the crack opening displacement (COD), which is considered as the product of the average unit COD and the strain component. Two sets of simulations are set at room temperature to validate the method in detail, to verify the mechanics of leakage due to the matrix cracks, and to find out the effect of the thin-plies on the leakage. This paper aims at providing new simulation schemes for damaged constitutive model, crack density prediction and leak rate estimation of the composite laminates.

中文翻译：

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基于裂纹密度的薄层复合材料层板泄漏率的半定量估计

摘要 为了预测基体裂纹引起的复合油箱泄漏，本文提出了新的模拟方案： (1) 提出了一种基于裂纹交叉区域的半定量泄漏率估计方法；(2) 半解析损伤本构模型是通过少量的微机械有限元分析(FEA)得到的；(3) 混合模式裂纹密度采用层合板有限元分析法估算，涉及渐进损伤特性；(4) 根据裂纹密度和裂纹张开位移（COD）估算裂纹相交面积，COD 被认为是平均单位 COD 和应变分量的乘积。在室温下设置两组模拟以详细验证该方法，以验证由于基体裂纹引起的泄漏力学，并找出薄层对泄漏的影响。本文旨在为复合材料层压板的损伤本构模型、裂纹密度预测和泄漏率估计提供新的模拟方案。