高温气冷堆石墨构件断裂性能数值研究

为探究球床模块式高温气冷堆（HTR-PM）石墨堆内构件抗断裂破坏特性，提供石墨堆内构件设计和完整性评估的依据，利用经实验验证的基于内聚力模型的扩展有限元方法（XFEM）对球床模块式高温气冷堆侧反射层石墨砖的燕尾键 键槽结构进行了断裂性能的模拟分析，并对石墨断裂参数及几何尺寸等参数进行了敏感性分析。模拟结果显示：该石墨砖燕尾键 键槽结构的最大失效载荷P_max为50.7 kN，且随圆角半径而增大；P_max对石墨材料抗拉强度敏感，圆角越大越敏感，对材料断裂功、杨氏模量敏感度较小，但随着结构圆角变小变得相对更敏感，对泊松比几乎不敏感。分析结果与文献预测及实验结论具有较好的一致性。本文研究能对其他类型反应堆（如熔盐堆和快堆）的石墨构件断裂性能分析评价提供参考。

Numerical Simulation of Graphite Component on Fracture Property in HTR-PM

For exploring the fracture property so as to provide evidence for the design and integrality assessment of graphite component in high temperature reactor pebble bed module (HTR-PM), extended finite element method with experimental verification which is based on the cohesive zone model was used to simulate the structure of graphite dovetail key-keyway. Also, sensitivity analysis of the fracture and geometric parameters was under consideration in the numerical analysis. The results show that maximum failure load of the graphite dovetail key-keyway structure is 50.7 kN, and increases with the corner radius. The maximum failure load is sensitive to the tensile strength, and becomes more sensitive with the increasing of the corner radius. The maximum failure load is less sensitive to the fracture energy as well as Young’s modulus, but turn into more sensitive with the decreasing of the corner radius. The maximum failure load is insensitive to the Poisson’s ratio. Great agreement is achieved between the simulation, literature predictions and experiments results. In addition, this paper would be practical to other types of reactors with graphite component such as molten salt reactor (MSR) and fast reactor.