Inclined multiple cracks may appear in composite laminates and sandwich structures. In this paper, we solve the fracture problem of a three-layer sandwich structure which contains multiple inclined cracks in the central layer under tension and antiplane shear. Three types of crack configurations are considered: an isolated crack, a periodic array of inclined cracks with the same length, and two parallel cracks with different lengths. In these cases, we examine the interaction among the cracks under mixed I–II mode and pure mode III based on the stress intensity factors. Then, we apply the solutions to fibre-reinforced composite laminates. The results show that the stress intensity factors of the multiple cracks are significantly affected by the constraining effect of the outer sublaminates and the shielding effect among cracks. For cracks with significantly different sizes, the long crack dominates the stress concentration. This work reveals the influences of the laminate configuration, crack distribution, crack orientation and crack size on the stress concentration at the tips of inclined cracks in the three-layer composite laminate, and the results may be used to analyze the crack propagation in the laminates.

中文翻译：

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面内载荷作用下复合层压板中多条倾斜裂纹的应力强度因子

复合层压板和夹层结构中可能会出现倾斜的多条裂缝。在本文中，我们解决了在张力和反平面剪切作用下中心层包含多个倾斜裂缝的三层夹层结构的断裂问题。考虑了三种类型的裂纹配置：孤立的裂纹、长度相同的倾斜裂纹的周期性阵列和两个不同长度的平行裂纹。在这些情况下，我们基于应力强度因子检查混合 I-II 模式和纯模式 III 下裂纹之间的相互作用。然后，我们将解决方案应用于纤维增强复合材料层压板。结果表明，多裂纹的应力强度因子受外层的约束作用和裂纹间的屏蔽作用显着影响。对于尺寸明显不同的裂纹，长裂纹在应力集中占主导地位。该工作揭示了层板结构、裂纹分布、裂纹方向和裂纹尺寸对三层复合层板斜裂纹尖端应力集中的影响，结果可用于分析层板裂纹扩展。 .