Testing the assumption of linear dependence between the rolling friction torque and normal force

Abstract

Abstract.Rolling friction is present in all nonconforming bodies in contact. A permanent topic is the characterization of the moment of rolling friction. A number of authors accept the hypothesis of linear dependency between the rolling torque and the normal force while other researchers disagree with this assumption. The present paper proposes a method for testing the hypothesis of linear relationship between rolling moment and normal pressing force. A doubly supported cycloidal pendulum is used in two situations: symmetrically and asymmetrically supported, respectively. Under the hypothesis of a linear relationship, the motions of the pendulum should be identical.

Considerations on finding the rolling and spinning friction coefficients

“…Under this power-law dependency the tribological and energetically study is obviously more complicated given that not only the coefficients s s and r s must be found, but also the exponents s  and r  from the relations 3 and 4. In a series of recent works, [6][7][8][9][10], there were presented several methods and the devices used in the estimation of either the coefficient of spinning friction or of the coefficient of rolling friction.…”