In order to obtain this correlation, some experimental tests have been carried out to measure the spread of the workpiece as a function of roll roughness; then, the spread has been evaluated by FEM simulation as a function of the friction coefficient.
Ra ------> experimetal tests -----> workpiece spread
]----> μ = f (Ra)
μ ------> FEM -----> workpiece spread
In order to verify the FEM simulation accuracy, experimental test and simulation results have been compared in terms of maximum height reduction obtainable.