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Combined peridynamics and finite element crystal plasticity modelling of the oxidation of zirconium alloys

锆合金氧化的近场动力学和有限元晶体塑性联合建模

基本信息

批准号：
2621911
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：
2021
资助国家：
英国
起止时间：
2021 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2621911
关键词：
Combined peridynamics finite element crystal

项目摘要

This project involves modelling the growing oxidation front on nuclear fuel cladding at the microscale. This is a complex multi-physics process involving diffusion of ionic species under temperature and stress gradients coupled to the mechanics of crack formation in the brittle oxide phase. Crack formation can both increase (through vertical cracking) or hinder (through lateral cracking) the oxygen and water molecule ingress to the metal-oxide interface. On top of this the cracking relieves the stresses that build up as the oxide thickens. Mechanistic understanding of the oxidation process is the aim of the project. This will in turn inform higher scale models of the oxide growth behaviour, which can ultimately determine the cladding and hence fuel life. Improving fuel life improves both the economics of plant operation and reduces the waste burden. To do this we will use two techniques that will ultimately be coupled together: (1) peridynamics, which is a non-local pseudo-meshless method that can model brittle cracking in the oxide phase, and (2) because this is a microscale phenomenon we will use finite element crystal plasticity modelling for the underlying zirconium metal. Together these methods will give the most complete model yet of the oxidation process of fuel cladding at this scale.

该项目涉及在微观尺度上模拟核燃料包壳上不断增长的氧化前沿。这是一个复杂的多物理过程，涉及温度和应力梯度下的离子物种的扩散，耦合到脆性氧化物相中的裂纹形成机制。裂纹形成可以增加（通过垂直裂纹）或阻碍（通过横向裂纹）氧和水分子进入金属-氧化物界面。除此之外，裂纹还能缓解氧化层增厚时产生的应力。对氧化过程的机理理解是该项目的目标。这将反过来告知氧化物生长行为的更高比例模型，这最终可以确定包壳，从而确定燃料寿命。延长燃料寿命既能提高工厂运行的经济性，又能减少废物负担。为了做到这一点，我们将使用两种技术，最终将耦合在一起：（1）周向波，这是一种非局部伪无网格方法，可以模拟氧化物相中的脆性开裂，（2）因为这是一种微观现象，我们将使用有限元晶体塑性建模的基础锆金属。这些方法结合起来将给出这个尺度下燃料包壳氧化过程的最完整的模型。