RUBBER AND TIRE FRICTION
Abstract
The mechanism of rubber friction is discussed, and an attempt is made to relate the friction characteristics of a rubber block to those of a slipping and sliding pneumatic tire. Several new or modified explanations of the behavior of tires on dry and wet surfaces are proposed. The effects of pressure or normal load, sliding velocity, temperature, and contaminating and lubricating films on the adhesion and hysteresis components are separately investigated for the rubber block and the rolling, slipping, and sliding tire. Attention is given to such topics as the existence or nonexistence of a static coefficient, the transient behavior of adhesive friction at nonsteady sliding velocities, the rise of the sliding coefficient with sliding velocity, comparison of the coefficients obtained from a sliding and a slipping tire, the meaning of slip, and the dependence of the critical coefficient on slip and vehicle velocity. Also explored are the mechanism of water removal between tire and road surface under wet driving conditions, and the effects of tire geometry, pressure distribution in the footprint, vehicle speed, and water film thickness on the obtainable coefficient. Experimental methods for measuring rubber and tire friction are reviewed. The Penn State brake test trailer is described.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1960
- Accession Number
- AD0660927
Entities
People
- H. W. Kummer
- W. E. Meyer
Organizations
- Pennsylvania State University