What is BS EN 843-5 - Weibull distribution of monolithic ceramics about?
BS EN 843 is a European standard series that discusses advanced technical ceramics.
BS EN 843-5 is the 5th part on the mechanical properties of monolithic ceramics at room temperature.
BS EN 843-5 specifies a method for statistical analysis of ceramic strength data in terms of a two-parameter Weibull distribution using a maximum likelihood estimation technique.
BS EN 843-5 assumes that the data set has been obtained from a series of tests under nominally identical conditions.
Note 1: In principle, Weibull analysis is considered to be strictly valid for the case of linear elastic fracture behaviour to the point of failure, i.e., for perfectly brittle material, and under conditions in which strength limiting flaws do not interact and in which there is only a single strength-limiting flaw population.
Note 2: BS EN 843-5 does not provide a method for dealing with censored data.
Note 3: If subcritical crack growth or creep deformation preceding fracture occurs, Weibull analysis can still be applied if the results fit a Weibull distribution, but numerical parameters may change depending on the magnitude of these effects.
Who is BS EN 843-5 - Weibull distribution of monolithic ceramics for?
BS EN 843-5 on the Weibull distribution of monolithic ceramics is useful for:
- Manufacturers of advanced technical ceramics
- The ceramic manufacturing industry
- Mechanical and chemical engineers
- Quality control and testing authorities
- Product development teams / Technical experts
- Industries including but not limited to aerospace and defence, healthcare, automotive, telecommunications, etc
- Regulatory bodies
Why should you use BS EN 843-5 – Weibull distribution of monolithic ceramics?
The strength of advanced technical ceramics is not usually a deterministic parameter. It depends on the nature, size and orientations of the flaws within the test piece relative to the stress field being applied. BS EN 843-5 applies to most monolithic advanced technical ceramics.
BS EN 843-5 provides guidance on the procedure to calculate the Weibull parameters using the maximum likelihood method.
The purpose of BS EN 843-5 is to provide unbiased estimates of the parameters of the underlying strength distribution of a population of ceramic test pieces in order to assess numerically the scatter in strengths of the population. There are a number of ways of determining such estimates, including least squares, moments, and maximum likelihood methods. The maximum likelihood method has been found to be the most efficient estimator for small sample numbers based on producing a smaller coefficient of variation of Weibull modulus, m, and for this reason it is chosen in BS EN 843-5.
Thus, BS EN 843-5 is your guide on accurate statistical analysis of monolithic ceramics, to demonstrate whether your materials present a risk of mechanical failure.