Tire Normal Force/Deflection and Gross Footprint Dimension Test
|Publication Date:||1 January 2005|
This SAE Recommended Practice describes a test method for determining the vertical force and deflection properties of a non-rolling tire and the associated contact patch length and width. The method applies to any tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development.
NOTE - Herein, road load models are models for predicting forces applied to the vehicle spindles during operation over irregular pavements. Within the context of this Recommended Practice, forces applied to the pavement are not considered.
Two procedures are specified. The first procedure produces tire normal force/deflection data. The second procedure produces gross footprint, tire contact area, dimensions. Properly applied, the second procedure can simultaneously produce both normal force/deflection data and gross footprint dimensions.
This document is test machine neutral. It may be applied using any type of test machine capable of fulfilling the requirements stated in this document. The test machine must be capable of accommodating the tire sizes which are to be tested.
This Recommended Practice was developed as part of a set of Recommended Practices intended to allow modelers to determine the parameters required by any of the common tire models for calculating spindle loads given the road surface profile from a single set of experimental results, and thus, to eliminate duplicate testing.