Estimation of coefficient of rolling friction by the evolvent pendulum method

Innovative Ideas in Science 2016

Alaci, S.^1 ; Ciornei, F.C.^1 ; Ciogole, A.^1 ; Ciornei, M.C.^2

Stefan Cel Mare University of Suceava, Mechanics and Technologies Department, Str. Universitatii no.13, Suceava

720229, Romania^1

Carol Davila University of Medicine and Pharmacy, Department 2 Physiology i, Bd. ErolilorSanitari no.8, Bucuresti, Romania^2

关键词: Angular amplitude;    Coefficient of rolling frictions;    Cylindrical bodies;    Cylindrical surface;    Equation of motion;    Equilibrium state;    Mechanical characteristics;    Theoretical modeling;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/200/1/012005/pdf
DOI  :  10.1088/1757-899X/200/1/012005

来源: IOP

【 摘 要 】

The paper presents a method for finding the coefficient of rolling friction using an evolvent pendulum. The pendulum consists in a fixed cylindrical body and a mobile body presenting a plane surface in contact with a cylindrical surface. The mobile body is placed over the fixed one in an equilibrium state; after applying a small impulse, the mobile body oscillates. The motion of the body is video recorded and afterwards the movie is analyzed by frames and the decrease with time of angular amplitude of the pendulum is found. The equation of motion is established for oscillations of the mobile body. The equation of motion, differential nonlinear, is integrated by Runge-Kutta method. Imposing the same damping both to model's solution and to theoretical model, the value of coefficient of rolling friction is obtained. The last part of the paper presents results for actual pairs of materials. The main advantage of the method is the fact that the dimensions of contact regions are small, of order a few millimeters, and thus is substantially reduced the possibility of variation of mechanical characteristic for the two surfaces.