Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Study on failure mechanism of line contact structures of nuclear graphite

  • Jia, Shigang (School of Aerospace Engineering, Beijing Institute of Technology) ;
  • Yi, Yanan (Department of Engineering Mechanics, Shanghai Jiaotong University) ;
  • Wang, Lu (School of Aerospace Engineering, Beijing Institute of Technology) ;
  • Liu, Guangyan (School of Aerospace Engineering, Beijing Institute of Technology) ;
  • Ma, Qinwei (School of Aerospace Engineering, Beijing Institute of Technology) ;
  • Sun, Libin (Institute of Nuclear and New Energy Technology, Tsinghua University) ;
  • Shi, Li (Institute of Nuclear and New Energy Technology, Tsinghua University) ;
  • Ma, Shaopeng (School of Aerospace Engineering, Beijing Institute of Technology)
  • Received : 2021.11.04
  • Accepted : 2022.03.13
  • Published : 2022.08.25
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Abstract

Line contact structures, such as the contact between graphite brick and graphite tenon, widely exist in high-temperature gas-cooled reactors. Due to the stress concentration effect, the line contact area is one of the dangerous positions prone to failure in the nuclear reactor core. In this paper, the failure mechanism of line contact structures composed of IG11 nuclear graphite column and brick were investigated by means of experiment and finite element simulation. It was found that the failure process mainly includes three stages: firstly, the damage accumulation in nuclear graphite material led to the characteristic yielding of the line contact structure, but no macroscopic failure can be observed at this stage; secondly, the stresses near the contact area met Mohr failure criterion, and a crack initiated and propagated laterally in the contact zone, that is, local macroscopic failure occurred at this stage; finally, a second crack initiated in the contact area and developed in to a Y-shape, resulting in the final failure of the structure. This study lays a foundation for the structural design and safety assessment of high-temperature gas-cooled reactors.

Keywords

Acknowledgement

This study was supported by the National Natural Science Foundation of China (Grant Nos. 11872115, U1837602, 11727801, 11772053 and 11602022) and the National S&T Major Project (Grant Nos. ZX06901 and ZX06907).

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