@article{737a99b7cf7046b3b19f31dad68ce733,
title = "Combined evaluation of Young modulus and fracture toughness in small specimens of fine grained nuclear graphite using 3D image analysis",
abstract = "The fracture toughness of the fine-grained nuclear graphite SNG742 has been investigated by observation of stable crack propagation in double cleavage drilled compression specimens. The three-dimensional displacement fields were obtained by digital volume correlation (DVC) of in situ laboratory X-ray computed tomographs. The crack tip location and crack opening displacements were determined using an image edge detection algorithm based on the wavelet modulus maxima. The Young modulus was estimated by fitting a finite element model to DVC displacement field data measured before crack initiation. Using the 3D crack geometry and the surrounding full-field 3D displacement fields as boundary conditions, the elastic strain energy release rate J and the three-dimensional stress intensity factors KI to KIII were then evaluated via the contour integral method. Constant mode I critical stress intensity factor was obtained along the curved crack fronts, with negligible shearing modes. This method allows evaluation of the fracture toughness without prior knowledge of elastic properties, and has potential applications to assess the effects of high temperature, oxidation and irradiation in small specimens of nuclear graphite.",
keywords = "Digital volume correlation, Double cleavage drilled compression, Fracture toughness, Graphite, Strain energy release rate",
author = "Jie Shen and Marrow, {T. James} and Daniel Scotson and Xiaochao Jin and Houzheng Wu and Hongniao Chen",
note = "Funding Information: Jie Shen and H. Chen gratefully acknowledges the support of the National Natural Science Foundation of China (Grant No. 51768011 ) and the China Scholarship Fund (Award No. 201906675001 ) that enabled their participation in this work. The materials were provided by Houzheng Wu, Loughborough University and the test specimen was fabricated by Sinosteel Ltd. The X-ray microscope, software and workstation used for the tomography and digital volume correlation analysis was supported by EPSRC Grant EP/M02833X/1 “University of Oxford: experimental equipment upgrade”. Funding Information: Jie Shen and H. Chen gratefully acknowledges the support of the National Natural Science Foundation of China (Grant No. 51768011) and the China Scholarship Fund (Award No. 201906675001) that enabled their participation in this work. The materials were provided by Houzheng Wu, Loughborough University and the test specimen was fabricated by Sinosteel Ltd. The X-ray microscope, software and workstation used for the tomography and digital volume correlation analysis was supported by EPSRC Grant EP/M02833X/1 “University of Oxford: experimental equipment upgrade”. Publisher Copyright: {\textcopyright} 2022 Elsevier B.V.",
year = "2022",
month = may,
doi = "10.1016/j.jnucmat.2022.153642",
language = "English",
volume = "563",
journal = "Journal of Nuclear Materials",
issn = "0022-3115",
publisher = "Elsevier BV",
}