Study on application of unified estimation for ceramic strength to reliability-design.

In order to study the optimizing for reliability-design ceramic components, a unified estimation method based on 3 parameter Weibull statistical analysis was developed by analyzing the fracture strength data obtained from various fracture tests on sintered SiC. The estimated results based on this method were compared with those estimated based on 2 parameter Weibull analysis about fitness for ceramic fracture strength properties. Furthermore special features for application of the unified estimation method to reliability-design were studied by applying it to the design of ceramic components for a gas turbine. The results obtained were as follows:1) The fracture strength of sintered-SiC can be estimated by the unified estimation method based on 3-parameter Weibull statistical analysis considering the lower limit strength.2) As for the normalized strength as a material constant obtained by the unified estimation method, the 3-parameter based estimation method gives a higher value than the 2-parameter based one.3) The unified estimation method based on 3 parameters is realistic for study of allowable stress against extremely low fracture probability in reliability-design.