Abstract
Lattice models allow length scale dependent micro-structural features and damage mechanisms to be incorporated into analyses of mechanical behaviour. They are particularly suitable for modelling the fracture of nuclear graphite, where porosity generates local failures upon mechanical and thermal loading. Our recent 3D site-bond model is extended here by representing bonds with spring groups. Experimentally measured distributions of pore sizes in graphite are used to generate models with pores assigned to the bonds. Microscopic damage is represented by failure of normal and shear springs with different criteria based on force and pore size. Macroscopic damage is analysed for several loading cases. It is shown that, apart from uniaxial loading, the development of micro-failures yields damage-induced anisotropy in the material. This needs to be accounted for in constitutive laws for graphite behaviour in FEA of cracked reactor structures.
Original language | English |
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Title of host publication | MSMF7 |
Place of Publication | Brno |
Publication status | Published - 1 Jul 2013 |
Event | 7TH International Conference on MATERIALS STRUCTURE & MICROMECHANICS OF FRACTURE - Brno, Czech Republic Duration: 1 Jul 2013 → 3 Jul 2013 |
Conference
Conference | 7TH International Conference on MATERIALS STRUCTURE & MICROMECHANICS OF FRACTURE |
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City | Brno, Czech Republic |
Period | 1/07/13 → 3/07/13 |
Keywords
- Nuclear graphite
- Porosity
- Meso-scale deformation
- Micro-cracks
- Macroscopic behaviour