Modelling of microstructure-sensitive short fatigue crack propagation in Zircaloy-4: influence of microstructure, hydrides, and irradiation

Zircloy-4 中微观结构敏感的短疲劳裂纹扩展的建模：微观结构、氢化物和辐照的影响

基本信息

批准号：
2462009
负责人：
金额：
--
依托单位：
Imperial College London
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2462009
关键词：
Modelling microstructure sensitive short fatigue

项目摘要

Rates of fatigue crack growth (FCG) and crack paths in Zircaloy-4 are highly microstructurally sensitive and dependent upon texture. This work is aimed at gaining mechanistic understanding of these microstructural effects. Crystal plasticity finite element modelling with the eXtended Finite Element Method and a stored energy density (SED) fracture criterion is used to simulate crack propagation in polycrystalline microstructures for comparison with experimental data. A new analytic solution for FCG rate is developed, facilitating rapid estimates. The model is based on a SED fracture criterion but is linked with classical fracture mechanics, enabling crack tip SED calculations at higher rates. Other work which is underway is aimed at capturing irradiation effects on short FCG rate. Dislocation channel clearing is being investigated in the presence of a crack. Additional experimental work is aimed at understanding the influence of hydrides on short FCG in Zircaloy-4. The first of a series of studies has begun. Lastly, studies will be carried out which will link previous work. The first aim will be to simulate previously mentioned experiments from incorporating the delta-hydride phase. The second aim will then be to incorporate the irradiation damage model for a theoretical assessment of irradiation damage on hydrided Zircaloy-4.

Zircloy-4 中的疲劳裂纹扩展 (FCG) 速率和裂纹路径对微观结构高度敏感，并且取决于织构。这项工作的目的是获得对这些微观结构效应的机械理解。使用扩展有限元法和存储能量密度 (SED) 断裂准则进行晶体塑性有限元建模来模拟多晶微结构中的裂纹扩展，以便与实验数据进行比较。开发了一种新的 FCG 率分析解决方案，有助于快速估算。该模型基于 SED 断裂准则，但与经典断裂力学相关，从而能够以更高的速率进行裂纹尖端 SED 计算。正在进行的其他工作旨在捕捉短 FCG 速率下的辐照效应。正在研究存在裂纹的情况下位错通道的清除。其他实验工作旨在了解氢化物对 Zircloy-4 中短 FCG 的影响。系列研究中的第一项研究已经开始。最后，将进行将以前的工作联系起来的研究。第一个目标是模拟前面提到的结合δ-氢化物相的实验。第二个目标是结合辐照损伤模型对氢化 Zircloy-4 的辐照损伤进行理论评估。