Tire penetration and rolling resistance

From Wikipedia, the free encyclopedia. Such torques results in energy dissipation above that due to the basic rolling resistance of a freely rolling, non-driven, non-braked wheel. In other projects Wikimedia Commons. It is defined by the following formula: Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. It is one of the forces that act to oppose the motion of a driver.

For railroads, this is called curve resistance but for roads it has at least once been called rolling resistance due to cornering. All rubber loses energy due to internal friction when it is deflected, since the energy required to deform rubber is greater than that required to return it to its original shape. Tire pressure, tire diameter, tire width, tire construction, tire tread and other factors all have an effect on rolling resistance. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation or movement of the wheel, roadbed, etc. Conversely, if the casing is bad, the tire will be slow, regardless of pressure.

Gavin, Three-dimensional boundary element formulation of an incompressible viscoelastic layer of finite thickness applied to the rolling resistance of a rigid sphere, International Journal of Solids and Structures, Volume 50, Issue 6, 15 March , Pages , ISSN , If a wider tire is constructed of the same materials in the same thicknesses as a narrower one, it will often roll faster on a rough surface, despite being heavier. For instance, the weight of the wheels is of great importance when this mass has to be brought up to rotation. The coefficient of rolling resistance for a slow rigid wheel on a perfectly elastic surface, not adjusted for velocity, can be calculated by [ citation needed ].

Textu re of test section SMAR on left and texture of reference section. This thesis concerns the deterioration of asphalt pavements due to the action of water and combined action of water and frost. As an example of a very heavy passenger train, in , Amtrak passenger trains weighed a little over 7 tonnes per passenger, [56] which is much heavier than an average of a little over one ton per passenger for an automobile. Wheel bearing torque losses can be measured as a rolling resistance at the wheel rim, Crr. The losses due to hysteresis also depend strongly on the material properties of the wheel or tire and the surface. CR bitumen may show higher stiffness modulus than reference SMA8 mixture in.