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Table 4.11 Overview of Tire Models

Tire type Data required Applicability
Fiala (Default) Basic tire properties Ÿ Handling analysis Ÿ Pure slip
University of Arizona (UA) Basic tire properties Ÿ Handling analysis Ÿ Comprehensive slip
Smithers Coefficients from fitted tire test data Ÿ Handling analysis Ÿ Pure slip
Delft Coefficients from fitted tire test data Ÿ Handling analysis Ÿ Comprehensive slip
User Defined User User

 

Default Dynamic Analysis Tire Model

An enhanced version of the so-called Fiala model is available as a default in ADAMS/Solver. The default tire model calculates tire forces in the longitudinal, lateral, and vertical directions as well as aligning moment and rolling resistance in response to slip angle, slip ratio and normal deflection. Camber thrust is not modeled. While rather simple, this model is capable of providing reliable results for situations not involving comprehensive slip, i.e., situations where longitudinal slip and lateral slip are not present simultaneously. This model is automatically invoked by ADAMS/Solver during a dynamic simulation involving tires translating at moderate to fast rates.

UA-Tire Dynamic Analysis Model

The UA-Tire model developed by Nikravesh and Gim at the University of Arizona, is part of the optional ADAMS/Tire module. The UA-Tire model computes normal, longitudinal, and lateral forces as well as aligning torque and rolling resistance under comprehensive slip

conditions. These forces and moments are determined by explicit formulations which are analytically derived depending on the coupled properties of slip ratio, slip angle, inclination angle, normal deflection, and other dynamic tire properties.

The UA-Tire model is much more comprehensive and accurate than the simpler Fiala model. It always provides much better results for aligning moments than the Fiala model. Additionally, in situations of comprehensive slip, the UA-Tire model provides much more realistic values for the other forces and torques.

Smithers Dynamic Analysis Tire Model

The Smithers tire model is part of the optional ADAMS/Tire module. This model is also referred to as the BNPS or Bakker-Nyborg-Pacejka-Smithers model. The Smithers model computes the lateral force and the aligning moment from the slip angle, inclination angle, vertical force, and data provided by Smithers Scientific Services. The Fiala tire model computes the other tire forces and torques. The Smithers model comes complete with three sample tire property files, which you can use until you obtain the specific tire property files for your perspective tires.

DELFT Dynamic Tire Model

The DELFT tire model is part of the optional ADAMS/Tire module. This model was developed by TNO Road-Vehicle Research Institute in the Netherlands. It is a Pacejka ˇ°magic formulaˇ± tire model. The model computes lateral, longitudinal, and vertical forces and the aligning moment from fitted coefficients TNO provides.




Date: 2015-12-18; view: 1144


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