The model for fracture toughness

It is pointed out that the distribution introduced by Neville [1] (for modeling fracture toughness to failures) is contained by at least two families of distributions known since the 1940s. Some elementary statistical properties of these families are discussed. Six data sets on fracture toughness are used to demonstrate that these families are much better models for fracture toughness than the one introduced by Neville [1].