The aim of this study is the formation and numerical-experimental background of the approach to assessing of the structural integrity based on the principles of tolerance damage and simulation modeling. To this end, constitutive equations of the Lemaitre model and phase field fracture are employed, which include damage functions for the stages of defect appearance and crack growth. A general system of resolving equations of isotropic and kinematic hardening, viscous plasticity and damage is formed, and a method for determining the parameters of these equations is developed and implemented in the ANSIS. The proposed method is invariant to the specific form of the equations and depends only on the nature of the behavior of the continuum. A distinctive feature of the proposed approach is the validation and verification of the low-cycle fatigue and phase field models using a simulation model. Low-cycle fatigue tests with measurements by digital image correlation of the displacement and strain fields around the holes and crack tip in the simulation model were performed. The fatigue lifetime and crack growth predictions are evaluated and compared using simulation model and a damaged in service power steam turbine disc with a blade rivet attachment as a case study.

中文翻译：

---

使用 FEM、DIC 和相场方法对受损涡轮盘的结构完整性进行全面研究


本研究的目的是基于公差损伤和模拟建模原则评估结构完整性的方法的形成和数值实验背景。为此，采用了 Lemaitre 模型和相场断裂的本构方程，其中包括缺陷出现和裂纹扩展阶段的损伤函数。形成了一个求解各向同性和运动硬化、粘性塑性和损伤方程的一般系统，并在 ANSIS 中开发和实施了确定这些方程参数的方法。所提出的方法对方程的特定形式是不变的，并且仅取决于连续体行为的性质。所提出的方法的一个显着特点是使用仿真模型对低周疲劳和相场模型进行验证和验证。通过对仿真模型中孔和裂纹尖端周围的位移和应变场进行数字图像关联进行低周疲劳测试。使用仿真模型和带有叶片铆钉附件的在役动力蒸汽轮机盘作为案例研究进行评估和比较疲劳寿命和裂纹扩展预测。