Abstract A model is described which allows the exact calculation of stresses in a cracked ply under combined state of strain. Closed form expressions for the stresses in each ply are combined in an energy density-based criterion to predict crack spacing and the resulting transverse modulus and shear modulus. Inelastic effects due to non-linearities of the ply-level shear stress-strain curve are accounted for through computation of the permanent shear strain in the ply. The model accounts for ply thickness, stacking sequence and load redistribution effects of a relatively broad class of laminates. Comparisons with test results for a variety of laminates and materials show very good to excellent agreement. The approach developed is extremely efficient and can easily be incorporated in numerical progressive failure analysis, where the stiffness properties of each element can be updated every time the crack pattern changes and in fatigue analysis where the stiffness of a ply or a laminate can be determined during every load cycle.

中文翻译：

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基体裂纹萌生和演化的预测及其对面内载荷下离轴层板层合板刚度的影响

摘要 描述了一个模型，该模型允许精确计算在组合应变状态下开裂层中的应力。每个层中应力的闭合形式表达式结合在基于能量密度的标准中，以预测裂纹间距以及由此产生的横向模量和剪切模量。由于层级剪切应力-应变曲线的非线性导致的非弹性效应通过计算层中的永久剪切应变来解释。该模型考虑了相对广泛的层压板的层厚度、堆叠顺序和载荷重新分配效应。与各种层压板和材料的测试结果的比较显示出非常好的一致性。开发的方法非常有效，可以很容易地结合到数值渐进式失效分析中，