高功率H模运行下钨铜偏滤器靶板热疲劳累积损伤分析

High power H mode is the reference operation mode for ITER and future tokamak fusion reactor. During the operation mode, the divertor target withstands complex time-evolution head loads combination of steady state ＞10MW/m2 and (ELMs, VDE) transient ~GW/m2, which would result in crack initiation / propagation or thermal fatigue damage accumulation and even failure in the tungsten surface and the interface between different materials. The mechanism of thermal fatigue damage initiation and propagation in W/Cu divertor target is necessarily further studied carefully. The proposed project, named 'Analysis of thermal fatigue damage accumulation for W/Cu divertor target under high power H mode operation', would focus on the study. Based on the EAST operation capability of ITER-like high power H mode, the 3D heat loads on divertor target will be analyzed by numerical simulation with PFCFlux and diagnostics on EAST. Then, with the elastic-plasic / mechanical facture finite element analysis technology and the theory of Linear fatigue damage accumulation, the mechanism of crack initiation and propagation will be investigated for the W/Cu divertor target. Furthermore, the fatigue life of W/Cu divertor target in EAST, ITER and future reactor will be analyzed, which should provide significantly important basis for the EAST future higher power H mode operation and the design and construction of the divertor in next step devices.

ITER及未来托卡马克聚变堆将以高功率H模运行为主。此运行模式中，偏滤器靶板将承受具有复杂时间历程的超过10MW/m2稳态和~GW/m2瞬态（ELMs、VDE）热负荷的叠加作用。钨铜偏滤器靶板的钨表面、不同材料界面结合处将存在裂纹萌生/扩展、热疲劳累积损伤及失效。多种热载荷共同作用导致的钨铜偏滤器靶板的热疲劳损伤的产生和变迁机理还有待深入研究。本项目将依托EAST具备类ITER高功率H模运行的能力，通过PFCFlux数值模拟和热负荷诊断数据综合分析获得偏滤器靶板的三维热负荷；以弹塑性/断裂力学有限元分析技术和线性疲劳累积损伤理论为基础，综合分析各热载荷在钨铜偏滤器靶板上引起的热/应力疲劳导致的损伤行为和累积效应；从裂纹萌生/扩展和疲劳寿命角度预测钨铜偏滤器在EAST、ITER及未来聚变堆中的服役性能，为EAST更高功率H模实验运行及下一代装置偏滤器的设计建造提供重要的理论依据

ITER及未来聚变堆将以H模运行模式为主。此运行模式中，偏滤器靶板将承受复杂时间历程的稳态和瞬态热负荷的叠加作用，钨铜偏滤器不同部位的热疲劳累计损伤和变迁机理是保证偏滤器安全可靠运行必须解决的关键科学技术问题之一。本项目依托EAST装置，基于PFCFlux数值模拟和红外相机诊断数据，分析了偏滤器靶板三维热负荷分布特征，构建了ELMs下偏滤器靶板热负荷的空间/时间分布函数；提出了钨铜偏滤器靶板结构损伤与疲劳寿命评判方法，建立了热-结构响应模型；完成了EAST钨铜偏滤器、CFETR钨铜偏滤器的热疲劳和高温蠕变的损伤累计分析；发现稳态高热负荷作用下，高温蠕变损伤将占主导地位。研究成果已应用于EAST/CFETR的钨铜偏滤器设计优化中，为未来聚变堆偏滤器运行的结构安全评估提供了基础数据和评估方法。项目执行过程中，在Nuclear Materials and Energy和Fusion Engineering and Design等聚变知名期刊发表SCI论文9篇，其中第一标注7篇；培养博士后出站1名、在站1名；项目组成员1人入选中国科学院青年创新促进会会员和安徽省百人计划。