The concluding sentence of section “Adding More Precise Contact Areas” states that, due to the changed contact area, not only the roll force but also the roll torque changed. Although this would be expected, it is unfortunately not reflected in the model's output. The reason is that the roll force - and thus the contact area - is not part of Lippmann and Mahrenholz’s formula for calculating the roll torque. That's why the torque remains the same despite the smaller contact area and, accordingly, the lower roll force.
For methodological reasons, it might therefore make sense to swap the order of the steps “Adding Influence of Friction and Shear” and “Adding More Precise Contact Areas” in the tutorial. This would restore the validity of the conclusions, even though it disguises the logical inconsistency of Lippmann and Mahrenholz’s formula in combination with Zouhar’s method for calculating the contact area.
The concluding sentence of section “Adding More Precise Contact Areas” states that, due to the changed contact area, not only the roll force but also the roll torque changed. Although this would be expected, it is unfortunately not reflected in the model's output. The reason is that the roll force - and thus the contact area - is not part of Lippmann and Mahrenholz’s formula for calculating the roll torque. That's why the torque remains the same despite the smaller contact area and, accordingly, the lower roll force.
For methodological reasons, it might therefore make sense to swap the order of the steps “Adding Influence of Friction and Shear” and “Adding More Precise Contact Areas” in the tutorial. This would restore the validity of the conclusions, even though it disguises the logical inconsistency of Lippmann and Mahrenholz’s formula in combination with Zouhar’s method for calculating the contact area.