Description / Abstract:
This SAE Recommended Practice describes an evaluation procedure
for validating tire models for use in road load simulations and
assesses the relevant dynamic behavior of tires.
The laboratory test utilized is a "cleat" test, where a rolling
tire on a drum encounters a cleat and the resulting dynamic forces
and moments are measured. This test is described in SAE J2730,
"Dynamic Cleat Test with Perpendicular and Inclined Cleats." The
test is commonly used to identify tire model parameters.
In this recommended practice, requirements for the measurement
of the tire's response are described along with data processing
techniques and calculations used to quantitatively compare the tire
model's calculated response to the tire's response measured on
test. This recommended practice addresses both the tire model
structure and its parameters.
NOTE 1: In this recommended practice, validation procedures are
proposed for assessing a single cleat test response, i.e., tire's
dynamic response for one operating condition consisting of
combination of vertical load, forward velocity, cleat size, shape,
and orientation, tire pressure, etc. However, it is insufficient to
validate a tire model based on a single test. In practice, this
assessment should be conducted over an entire set of operating
conditions which are selected in such a way as to cover the range
of road load simulation applications for which the tire model will
be utilized.
NOTE 2: The procedures defined in this recommended practice aim
to assess the relevant tire dynamic behavior for road load
simulations. It is recommended that the following additional tire
properties be determined separately:
•Normal force and rolling radius of the steady-state
rolling tire (i.e., the rolling tire in the absence of vertical
excitations such as cleats) at various loaded radii and forward
velocities relevant for the application.
•Static tire footprint dimensions vs. normal force. (See
SAE J2704.)
•Tire quasi-static longitudinal force vs. longitudinal
displacement and quasi-static lateral force vs. lateral
displacement. (See SAE J2718.)
•Steady-state force and moment characteristics. (See SAE
J2047.)