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Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel) rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement) of the wheel, roadbed, etc., is recovered when the pressure is removed.
This theory is exact for the situation of an infinite friction coefficient in which case the slip area vanishes, and is approximative for non-vanishing creepages. It does assume Coulomb's friction law, which more or less requires (scrupulously) clean surfaces. This theory is for massive bodies such as the railway wheel-rail contact.
rolling friction. In the case of bodies capable of rolling, there is a particular type of friction, in which the sliding phenomenon, typical of dynamic friction, does not occur, but there is also a force that opposes the motion, which also excludes the case of static friction. This type of friction is called rolling friction.
SAE J1269 and SAE J2452 performed on new tires. SAE J2452 is a standard defined by the Society of Automotive Engineers [1] to measure the rolling resistance of tires. [2] Where the older standard, SAE J1269, produces measurements of rolling resistance under steady-state (i.e. thermally equilibrated) operating conditions, SAE J2452 produces measurements during a transient history of speed that ...
Traction can also refer to the maximum tractive force between a body and a surface, as limited by available friction; when this is the case, traction is often expressed as the ratio of the maximum tractive force to the normal force and is termed the coefficient of traction (similar to coefficient of friction).
Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. [7] [8] Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. [9] [10] [11] Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body.
Calculating rolling returns isn’t difficult to do, and it’s something to consider if you’re focused on the long-term with your investment strategy. Tips for Investing.
The life of a rolling bearing is expressed as the number of revolutions or the number of operating hours at a given speed that the bearing is capable of enduring before the first sign of metal fatigue (also known as spalling) occurs on the race of the inner or outer ring, or on a rolling element. Calculating the endurance life of bearings is ...