BS ISO 20501:2019 pdf free

BS ISO 20501:2019 pdf free.Fine ceramics (advanced ceramics, advanced technical ceramics) – Weibull statistics for strength data
In method B, begin by performing a fractographic examination of each failed specimen in order to characterize fracture origins. Screen the data associated with each flaw distribution for outliers. If all failures originate from a single flaw distribution compute an unbiased estimate of the Weibull modulus,and compute confidence bounds for both the estimated Weibull modulus and the estimated Weibull characteristic strength. If the failures originate from more than one flaw type, separate the data sets associated with each flaw type, and subject these individually to the censored analysis. Finally, prepare a graphical representation of the failure data along with a test report. When using the results of the analysis for design purposes it should be noted that there is an implicit assumption that the flaw populations in the strength test pieces and the components are of the same types.
This document outlines the application of parameter estimation methods based on the maximum likelihood technique (see also References [13]， [14]， [20] and [21]). This technique has certain advantages. The parameter estimates obtained using the maximum likelihood technique are unique (for a two-parameter Weibull distribution), and as the size of the sample increases, the estimates statistically approach the true values of the population more efficiently than other parameter estimation techniques.
The application of the techniques presented in this document can be complicated by the presence of test specimens that fail from extraneous flaws, fractures that originate outside the effective gauge section, and unidentified fracture origins. If these complications arise, the strength data from these specimens should generally not be discarded. Strength data from specimens with fracture origins outside the effective gauge section[3] and from specimens with fractures that originate from extraneous flaws should be censored, and the maximum likelihood methods presented in method B (Clause 7) are applicable. It is imperative that the number of unidentified fracture origins, and how they were classified, be stated in the test report. A discussion of the appropriateness of each option can be
found in 7.2.2.BS ISO 20501 pdf free download.