Modelling fracture of aged graphite bricks under radiation and temperature
The graphite bricks of the UK carbon dioxide gas cooled nuclear reactors are subjected to neutron irradiation and radiolytic oxidation during operation which will affect thermal and mechanical material properties and may lead to structural failure. In this paper, an empirical equation is obtained an...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Published: |
Elsevier
2017
|
| Subjects: | |
| Online Access: | https://eprints.nottingham.ac.uk/41208/ |
| _version_ | 1848796221408280576 |
|---|---|
| author | Hashim, Atheer Kyaw, Si Sun, Wei |
| author_facet | Hashim, Atheer Kyaw, Si Sun, Wei |
| author_sort | Hashim, Atheer |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | The graphite bricks of the UK carbon dioxide gas cooled nuclear reactors are subjected to neutron irradiation and radiolytic oxidation during operation which will affect thermal and mechanical material properties and may lead to structural failure. In this paper, an empirical equation is obtained and used to represent the reduction in the thermal conductivity as a result of temperature and neutron dose. A 2D finite element thermal analysis was carried out using Abaqus to obtain temperature distribution across the graphite brick. Although thermal conductivity could be reduced by up to 75% under certain conditions of dose and temperature, analysis has shown that it has no significant effect on the temperature distribution. It was found that the temperature distribution within the graphite brick is non-radial, different from the steady state temperature distribution used in the previous studies [1, 2]. To investigate the significance of this non-radial temperature distribution on the failure of graphite bricks, a subsequent mechanical analysis was also carried out with the nodal temperature information obtained from the thermal analysis. To predict the formation of cracks within the brick and the subsequent propagation, a linear traction–separation cohesive model in conjunction with the extended finite element method (XFEM) is used. Compared to the analysis with steady state radial temperature distribution, the crack initiation time for the model with non-radial temperature distribution is delayed by almost one year in service, and the maximum crack length is also shorter by around 20%. |
| first_indexed | 2025-11-14T19:44:32Z |
| format | Article |
| id | nottingham-41208 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:44:32Z |
| publishDate | 2017 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-412082020-05-04T18:41:40Z https://eprints.nottingham.ac.uk/41208/ Modelling fracture of aged graphite bricks under radiation and temperature Hashim, Atheer Kyaw, Si Sun, Wei The graphite bricks of the UK carbon dioxide gas cooled nuclear reactors are subjected to neutron irradiation and radiolytic oxidation during operation which will affect thermal and mechanical material properties and may lead to structural failure. In this paper, an empirical equation is obtained and used to represent the reduction in the thermal conductivity as a result of temperature and neutron dose. A 2D finite element thermal analysis was carried out using Abaqus to obtain temperature distribution across the graphite brick. Although thermal conductivity could be reduced by up to 75% under certain conditions of dose and temperature, analysis has shown that it has no significant effect on the temperature distribution. It was found that the temperature distribution within the graphite brick is non-radial, different from the steady state temperature distribution used in the previous studies [1, 2]. To investigate the significance of this non-radial temperature distribution on the failure of graphite bricks, a subsequent mechanical analysis was also carried out with the nodal temperature information obtained from the thermal analysis. To predict the formation of cracks within the brick and the subsequent propagation, a linear traction–separation cohesive model in conjunction with the extended finite element method (XFEM) is used. Compared to the analysis with steady state radial temperature distribution, the crack initiation time for the model with non-radial temperature distribution is delayed by almost one year in service, and the maximum crack length is also shorter by around 20%. Elsevier 2017-04-11 Article PeerReviewed Hashim, Atheer, Kyaw, Si and Sun, Wei (2017) Modelling fracture of aged graphite bricks under radiation and temperature. Nuclear Materials and Energy, 11 . pp. 3-11. ISSN 2352-1791 Nuclear graphite neutron dose irradiation temperature damage model crack growth http://www.sciencedirect.com/science/article/pii/S2352179117300017 doi:10.1016/j.nme.2017.03.038 doi:10.1016/j.nme.2017.03.038 |
| spellingShingle | Nuclear graphite neutron dose irradiation temperature damage model crack growth Hashim, Atheer Kyaw, Si Sun, Wei Modelling fracture of aged graphite bricks under radiation and temperature |
| title | Modelling fracture of aged graphite bricks under radiation and temperature |
| title_full | Modelling fracture of aged graphite bricks under radiation and temperature |
| title_fullStr | Modelling fracture of aged graphite bricks under radiation and temperature |
| title_full_unstemmed | Modelling fracture of aged graphite bricks under radiation and temperature |
| title_short | Modelling fracture of aged graphite bricks under radiation and temperature |
| title_sort | modelling fracture of aged graphite bricks under radiation and temperature |
| topic | Nuclear graphite neutron dose irradiation temperature damage model crack growth |
| url | https://eprints.nottingham.ac.uk/41208/ https://eprints.nottingham.ac.uk/41208/ https://eprints.nottingham.ac.uk/41208/ |