In this two-part paper, guidance for assessing plates containing embedded elliptical cracks under complex loading conditions is developed, based on the fracture mechanics validation of the limit load solutions using the finite element (FE) J solutions. In Part I of this paper, elastic-plastic 3D FE analyses are performed for plates with embedded off-set elliptical cracks under combined biaxial stresses and through-thickness bending for developing a FE J database containing 612 cases. Totally 18 cracked plate models are created. For each cracked plate, 17 load combinations are considered and two material strain hardening exponents are analysed. The obtained plastic J solutions are correlated as the EPRI type fully-plastic J factor h₁. The effect of the applied normal stress parallel to the crack plane, σ₂, on the elastic-plastic J behaviour is investigated and it is found that the EPRI linear addition J estimation scheme may not describe the elastic-plastic J behaviour very well for cases under combined bending moment and σ₂. The limit load validation using the FE J solutions is detailed in Part II of this paper.

在这篇由两部分组成的论文中，基于使用有限元 (FE) J解法对极限载荷解法进行的断裂力学验证，制定了在复杂载荷条件下评估包含嵌入椭圆裂纹的板的指南。在本文的第一部分，对在双轴应力和全厚度弯曲下具有嵌入偏移椭圆裂纹的板进行弹塑性 3D 有限元分析，以开发包含 612 个案例的有限元J数据库。共创建了 18 个裂纹板模型。对于每个裂纹板，考虑了 17 种载荷组合，并分析了两种材料应变硬化指数。得到的塑性J解与 EPRI 型全塑性J因子相关ħ ₁。研究了平行于裂纹平面的正应力σ ₂对弹塑性J行为的影响，发现 EPRI 线性加法J估计方案​​可能不能很好地描述弹塑性J行为的情况在组合弯矩和σ _{2 下}。本文的第二部分详细介绍了使用 FE J解决方案进行的极限载荷验证。