The macroscopic tensile strength of a panel containing a centre-crack or a centre-hole is predicted, assuming the simultaneous activation of multiple cohesive zones. The panel is made from an orthotropic elastic solid, and the stress raiser has both a tensile cohesive zone ahead of its tip, and shear cohesive zones in an orthogonal direction in order to represent two simultaneous damage mechanisms. These cohesive zones allow for two modes of fracture: (i) crack extension by penetration, and (ii) splitting in an orthogonal direction. The sensitivity of macroscopic tensile strength and failure mode to the degree of orthotropy is explored. The role of notch acuity and notch size are assessed by comparing the response of the pre-crack to that of the circular hole. This study reveals the role of the relative strength and relative toughness of competing damage modes in dictating the macroscopic strength of a notched panel made from an orthotropic elastic solid. Universal failure mechanism maps are constructed for the pre-crack and hole for a wide range of material orthotropies. The maps are useful for predicting whether failure is by penetration or kinking. Case studies are developed to compare the predictions with observations taken from the literature for selected orthotropic solids. It is found that synergistic strengthening occurs: when failure is by crack penetration ahead of the stress raiser, the presence of shear plastic zones leads to an enhancement of macroscopic strength. In contrast, when failure is by crack kinking, the presence of a tensile plastic zone ahead of the stress raiser has only a mild effect upon the macroscopic strength.

中文翻译：

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正交各向异性固体的缺口敏感性：拉伸和剪切损伤区的相互作用

假设多个粘合区域同时激活，可以预测包含中心裂纹或中心孔的面板的宏观拉伸强度。该面板由正交各向异性弹性固体制成，应力集中在其尖端之前具有拉伸内聚区域，并且在正交方向上具有剪切内聚区域，以代表两种同时发生的损伤机制。这些内聚区允许两种断裂模式：(i) 裂纹通过穿透扩展，以及 (ii) 沿正交方向分裂。探讨了宏观拉伸强度和失效模式对正交各向异性程度的敏感性。通过比较预裂纹与圆孔的响应来评估缺口锐度和缺口尺寸的作用。这项研究揭示了竞争损伤模式的相对强度和相对韧性在决定由正交各向异性弹性固体制成的缺口面板的宏观强度中的作用。为各种材料正交各向异性的预裂纹和孔构建了通用失效机制图。这些图对于预测失效是由于穿透还是扭结非常有用。开展案例研究，将预测与文献中针对选定正交各向异性固体的观察结果进行比较。研究发现，会发生协同强化：当应力集中点之前的裂纹穿透导致失效时，剪切塑性区的存在会导致宏观强度的增强。相比之下，当裂纹扭结导致失效时，应力集中源之前拉伸塑性区域的存在对宏观强度仅产生轻微影响。