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 [C. Truesdell, The natural time of a viscoelastic fluid: its significance and measurement, Phys. Fluids 7 (8) (1964) 1134–1142] 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 stress-deformation 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.