ADAMS/Tire  

Support for user-defined tire and road models 

We are pleased to announce that the process of linking user-defined tire and road models with MSC.ADAMS has been enhanced in the 2003 release of ADAMS/Tire. In previous versions, user-defined tire and road models were supported only with in our vehicle applications: ADAMS/Car and ADAMS/Chassis.

Accessing this new feature

1. In the [MODEL] block of the tire or road data file, you need to have the keywords PROPERTY_FILE_FORMAT and FUNCTION_NAME specifying the entry point to the user tire or road functions.
   
   Example
   $-----------------------------------------------model
   [MODEL]
   PROPERTY_FILE_FORMAT = 'USER'
   FUNCTION_NAME = 'USERTIRE'
   $-----------------------------------------------model
   
   
2. Compile and link the user functions with MSC.ADAMS to create a user executable.

Example
On UNIX, type the following command at in a shell window:

   adams -c cr-u n usertire.f -n test.so exit      

On Windows:

• Compile the function usertire.f:
  
   df /c /architecture:p6 /Ob2 /MD usertire.f
  
  
• Link the object file usertire.obj against ADAMS/Solver:
  
   adams cr-u n usertire.obj -n test.dll exit
  

  where:
  - usertire.f contains the force evaluation functions for
     the user tire model.
  - test.so and test.dll are the user solver library.

During runtime the function 'USERTIRE' will be registered and called to evaluate the tire/road model.

Zero-speed capability implementation extended to all handling tire models 

The slip calculations for all of the handling tire models have been enhanced to allow the tire to perform at low or zero speed. This capability has been added to the following tire models in the ADAMS/Tire Handling package:

• University of Arizona
• Fiala
• Pacejka '89
• Pacejka '94
• 5.2.1 Equation and Interpolation method

Automatic mirroring (symmetry) added for MF-Tyre and
MF-MCTYRE

Automatic mirroring (symmetry) has been added to MF-Tyre. A new keyword in the tire property file in the [MODEL] section is needed. The three options are:

• TYRESIDE ='LEFT'
• TYRESIDE ='RIGHT'
• TYRESIDE ='SYMMETRIC'

When the tire is defined as being on the right-hand side (RHS) of the vehicle and the tire property file indicates that the measurement was done for a LHS tire, (indicated by TYRESIDE='LEFT') then automatic mirroring will be applied (and the reverse). SYMMETRIC removes all asymmetrical behavior from the tire data.

If keyword TYRESIDE is not present, the behavior will be as before for backward compatible.

Support for 3D-equivalent volume road model in FTire

FTire now supports the 3D equivalent road model. New improvements to FTire include:

• Improved accuracy for high-rolling speeds by limiting rotation angle increment in every integration step.

• Optional preprocessing for two different inflation pressures to improve accuracy of pressure dependency.

• Improved tire properties output using fast dynamic simulation during preprocessing:
  • Rolling-speed dependent vertical stiffness
  • Cornering stiffness
  • Longitudinal slip stiffness
    
    

• Control and change operating conditions inflation pressure and tread depth during simulation.

• Display road profile/road surface (both for road method 2D and 3D) in animated FTire version (Windows only).

• Supports the 3D-equivalent volume road method (used for durability simulations).

• Improvements in data supply for truck tires now available with FTire.

Items introduced in the 12.0 Service Pack and included in the 2003 release

The 2003 release of ADAMS/Tire includes items that were introduced in the 12.0 Service Pack. If you did not installed the 12.0 Service Pack for your MSC.ADAMS installation, we would like to announce that the following items have also been included in the standard 2003 release of ADAMS/Tire:

30292
A new 3D Spline Road module is available from MSC.Software. ADAMS/3D Road allows you to create many types of three-dimensional roads, such as parking structures, race, tracks, and so on. The ADAMS/3D Road profiles are defined in the .rdf (TeimOrbit) text file format. You can then incorporate this .rdf file into both ADAMS/Car and ADAMS/Chassis models and use with ADAMS/Tire Handling Tire.

For the 12.0 Service Pack release, only smooth 3D roads are supported (that is, no bumps, potholes, and so on). The same road perturbations that are available in 2D road will be extended to 3D road in a future release. The highly advanced road module algorithms and code were developed for MSC.Software by Yoav Lahav (www.genesim.co.il). For more information, please see the Using ADAMS/Tire Road Models online guide.

ADAMS/3D Road is a new product. If you are interested in purchasing ADAMS/3D Road, please contact your local MSC.Software Account Manager or Sales Administrator.

32368
The Creating User Tire and Road Models online guide now includes documentation for the valid unit choices in the tire and road property files.