Progress in Developing Finite Element Models Replicating Flexural Graphite Testing

Robert Bratton

关键词: CERAMICS;    COMPRESSION;    DESIGN;    FLEXURAL STRENGTH;    FRACTURES;    GRAPHITE;    NUCLEAR ENGINEERING;    PROBABILITY;    STATISTICAL MODELS;    TENSILE PROPERTIES;    TESTING finite elements;    NGNP;   

DOI  :  10.2172/989881
RP-ID  :  INL/EXT-10-18882
PID  :  OSTI ID: 989881
Others  :  TRN: US1007242

学科分类：核能源与工程

美国|英语

来源: SciTech Connect

【 摘 要 】

This report documents the status of flexural strength evaluations from current ASTM procedures and of developing finite element models predicting the probability of failure. This work is covered under QLD REC-00030. Flexural testing procedures of the American Society for Testing and Materials (ASTM) assume a linear elastic material that has the same moduli for tension and compression. Contrary to this assumption, graphite is known to have different moduli for tension and compression. A finite element model was developed and demonstrated that accounts for the difference in moduli tension and compression. Brittle materials such as graphite exhibit significant scatter in tensile strength, so probabilistic design approaches must be used when designing components fabricated from brittle materials. ASTM procedures predicting probability of failure in ceramics were compared to methods from the current version of the ASME graphite core components rules predicting probability of failure. Using the ASTM procedures yields failure curves at lower applied forces than the ASME rules. A journal paper was published in the Journal of Nuclear Engineering and Design exploring the statistical models of fracture in graphite.