SAE J2731_201205

1. SCOPE
2. REFERENCES
3. DEFINITIONS
4. NOMENCLATURE
5. LABORATORY QUALITY SYSTEM REQUIREMENT
6. APPARATUS
7. CALIBRATION
8. PREPARATION OF APPARATUS
9. SELECTION AND PREPARATION OF TEST TIRES
10. TEST PROCEDURE
11. DATA PROCESSING AND REPORTING
12. DATA REPEATABILITY AND REPRODUCIBILITY
13. NOTES

Specifies a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed.

This SAE Recommended Practice describes a test method for measuring the forces and moments generated at a spindle when a tire rolls over a rectangular obstacle, cleat, at very low speed. The cleat used in a particular test condition is configured with its crest either perpendicular, 90°, to the path of the tire or optionally with its crest inclined at an angle to the path of the tire. The carriage to which the spindle is attached is rigidly constrained in position during each test condition so as to provide a good approximation to fixed loaded radius operation. The method discussed in this document provides cleat envelopment force and moment and tire angular position histories as functions of distance traveled. These histories are essentially free from variations due to tire non-uniformities. The method applies to any size 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 surfaces, paved or otherwise. Within the context of this document, forces applied to the road or terrain surface are not considered.