Dimensionless correlation for sand erosion of families of polymers

A single correlation for sand erosion of a “family” of polyurethanes is presented. By “family” is meant a group of chemically similar compounds. For the first time, an implication of Truesdell’s [1] observations regarding the number of dimensional parameters in viscoelastic constitutive equations has been used together with the Pi theorem to prepare a single dimensionless correlation for a group of materials with similar but different forms of constitutive equations, different forms of stressdeformation behavior. To this point, such correlations have been for materials having the same form of constitutive equation, such as Hooke’s law or Newton’s law of viscosity.