Description / Abstract:
This SAE Recommended Practice describes a test method for
measuring the forces and moments generated at a high frequency
response spindle when a rolling tire impacts a cleat. The cleat is
configured either with its crest 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 impact force and moment
time histories 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.