Fracture Stress Data for SiC Layers in the TRISO-Coated Fuel Particles
A crush testing method for hemispherical shell specimens was developed based on the result of finite element (FE) analysis on stress distribution, and was applied to the evaluation of fracture strength for the chemical vapor deposited (CVD) SiC layers of tri-isotropic (TRISO) fuel particles. This report presents descriptions on the testing and evaluation procedures, SiC fracture data, and Weibull statistics parameters. In the mechanical testing, hemispherical shell specimens of SiC layers removed from TRISO particles were diametrically loaded between a bottom base and a plunger with brass foil at its end. The fracture in the shells always initiates at the inner surface below the loading contact at the convex (outer) surface. Producing a highly uniform stress distribution under the loading contact area is necessary to accurately evaluate the fracture stress from the measured fracture load data by using an analytical solution. Finite element analysis confirms that a relatively soft metal (brass foil) inserted between the specimen’s convex surface and plunger tip produced a highly uniform stress distribution under the contact area. Some conventional crust test methods without defining effective volume or area cause difficulties in interpretation of fracture strength data because a strong size effect exists in the fracture test results from miniature specimens. In this study a major improvement was made by using a simple experimental method to obtain the effective area.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1616803
- Report Number(s):
- ORNL/TM-2008/167; TRN: US2106474
- Country of Publication:
- United States
- Language:
- English
Similar Records
INFUENCE OF SPECIMEN TYPE AND LOADING CONFIGURATION ON THE FRACTURE STRENGTH OF SiC LAYER IN COATED PARTICLE FUEL
Evaluation of the Fracture Strength for SiC Layers in the TRISO-coated Fuel Particle