Road Load Tire Model Validation Procedures for Dynamic Behavior
|Publication Date:||1 February 2014|
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.)