ONORM EN 843-5 : AUG 2007

Foreword
1 Scope
2 Normative references
3 Terms and definitions
  3.1 Flaws
  3.2 Flaw distributions
  3.3 Mechanical evaluation
  3.4 Statistical terms
  3.5 The Weibull distribution
4 Symbols
5 Significance and use
6 Principle of calculation
  6.1 Maximum likelihood method
  6.2 Bias correction
  6.3 Confidence interval
7 Procedure
  7.1 Graphical representation of data
  7.2 Determination of Weibull parameters
      by maximum likelihood method
  7.3 Determination of limits of the confidence
      interval
8 Test report
Annex A (informative) Relationship between
        characteristic strengths of test pieces
        or components of different size or
        shape, or with different stress fields
        applied
Annex B (informative) FORTRAN program for
        calculating Weibull parameters
Annex C (informative) PASCAL program for
        calculating Weibull parameters
Annex D (informative) BASIC program for
        calculating Weibull parameters
Annex E (normative) Unbiasing factors for
        estimation of Weibull modulus, m
Annex F (normative) Confidence factors for
        characteristic strength, sigma[0]
Annex G (normative) Confidence factors for
        Weibull modulus, m
Annex H (informative) Worked examples
Annex I (informative) Example test report
Bibliography

Describes a method for statistical analysis of ceramic strength data in terms of a two-parameter Weibull distribution using a maximum likelihood estimation technique. It assumes that the data set has been obtained from a series of tests under nominally identical conditions.