Abstract
To develop guidelines for using C-ring specimens for evaluating the fracture strength of ceramics in tubular form, a series of finite-element analysis (FEA) calculations was performed. These calculations focused on the ranges of specimen dimensions and loading distributions required to maintain a uniaxial stress state within the C-ring specimen under diametral loading. Results of the FEA calculations indicated that the degree of uniaxiality of the C-ring stress state could be described completely by a combination of the width-to-thickness ratio (b/t) and the inner radius-to-outer radius ratio (ri/ro). It was also found that a reasonably wide range of geometries can be used with accuracy to extract fracture strength design data, provided b/t does not get too large or ri/ro too low. Given the potential statistical distribution of flaws in most ceramics, there is also cause for concern when b/t®0 or ri/ro®1 as this implies a small sample of flaws in the critical tensile stress region. Calculations also indicated that the uniaxiality of the C-ring stress state followed the expected 1/n dependence so that the behaviors of different materials can be surmised easily from the current results calculated for n=0.155. As expected, and in contrast to O-ring specimens, the loading distribution between the C-ring surface and platum do not seem to have any effect on the stress state.
Keywords:
C-Ring, dimensional guidelines, finite-element analysis, Fracture strength, tests, uniaxiality
Paper ID: JTE11965
DOI: 10.1520/JTE11965
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Author Embree, TL Affiliation Washington State University at Vancouver
Author Segall, AE Affiliation The Pennsylvania State University, University Park, PA
Author Embree TL, Segall AE
Title Evaluation of the Uniaxiality of the Stress State in C-Ring Fracture Strength Specimens
Symposium ,
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