Search results
Results from the WOW.Com Content Network
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.
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 ...
The rolling resistance coefficient (RRC) indicates the amount of force required to overcome the hysteresis of the material as the tire rolls. Tire pressure, vehicle weight and velocity all play a role in how much force is lost to rolling resistance. The basic model equation for SAE J2452 is: Rolling Resistance (N / lbs) = (+ +) where: is the ...
Rolling resistance is the force that resists the rolling of a wheel or other circular object along a surface caused by deformations in the object or surface. Generally the force of rolling resistance is less than that associated with kinetic friction. [74] Typical values for the coefficient of rolling resistance are 0.001. [75]
SAE J1269 is a standard test defined by the Society of Automotive Engineers [1] to measure the rolling resistance of tires under conditions of thermal equilibrium. [2] [3] SAE J2452 is an alternative procedure for measuring rolling resistance under conditions similar to a vehicle coastdown event, where the tire is in a roughly isothermal condition (but not thermal equilibrium).
Force variation axes. Tire forces are divided into three axes: radial, lateral, and tangential (or fore-aft). The radial axis runs from the tire center toward the tread, and is the vertical axis running from the roadway through the tire center toward the vehicle.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
For example, in the USSR, the standard formula is Wr (curve resistance in parts per thousand or kgf/tonne) = 700/R where R is the radius of the curve in meters. Other countries often use the same formula, but with a different numerator-constant. For example, the US used 446/R, Italy 800/R, England 600/R, China 573/R, etc.