Revisiting the Recommended Geometry for the Diametrally Compressed Ceramic C-Ring Specimen

Jadaan, Osama M. ; Wereszczak, Andrew A

Oak Ridge National Laboratory

关键词: Probability;    Ultimate Strength;    Forecasting;    Geometry;    Ambient Temperature;   

DOI  :  10.2172/950808
RP-ID  :  ORNL/TM-2009/090
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  950808

美国|英语

来源: UNT Digital Library

【 摘 要 】

A study conducted several years ago found that a stated allowable width/thickness (b/t) ratio in ASTM C1323 (Standard Test Method for Ultimate Strength of Advanced Ceramics with Diametrally Compressed C-Ring Specimens at Ambient Temperature) could ultimately cause the prediction of a non-conservative probability of survival when the measured C-ring strength was scaled to a different size. Because of that problem, this study sought to reevaluate the stress state and geometry of the C-ring specimen and suggest changes to ASTM C1323 that would resolve that issue. Elasticity, mechanics of materials, and finite element solutions were revisited with the C ring geometry. To avoid the introduction of more than 2% error, it was determined that the C ring width/thickness (b/t) ratio should range between 1-3 and that its inner radius/outer radius (ri/ro) ratio should range between 0.50-0.95. ASTM C1323 presently allows for b/t to be as large as 4 so that ratio should be reduced to 3.