Fiala Tire
The FIALA tire model serves as the first stepping stone in full vehicle simulation because it is simple enough to be comprehended completely by the MBD analyst. Furthermore, the forces and torques produced by the tire/road interaction use a series of physically meaningful parameters.
On the other hand, the FIALA tire model makes a series of assumptions
when computing forces and torques. These restrict its applicability only to a limited set of
vehicle maneuvers that do not violate the following simplifications:
- Rectangular shape of the contact patch.
- Uniform distribution of contact patch forces.
- Gyroscopic torques due to the inertia of the tire carcass are neglected. However, these may be accounted for by adding the mass and inertia of the tire to the wheel.
This model has been updated to include the effects of camber forces and moments. It is important to keep in mind that no real tire behaves as described above, therefore the applicability of the FIALA tire model is limited primarily to vehicle handling on smooth road surfaces.
There are two versions of Fiala in MotionSolve; one with only steady state force calculation and the other
implements the tire relaxation effects. The model is chosen based on the
“property_file_format” attribute in tire property file.
- Fiala with steady state forces - To use this version of FIALA the tire property file
should contain the following attribute:
- property_file_format = ‘FIALA’
- Fiala with tire relaxation effects - To use this version the property file should
contain the following attributes:
- property_file_format = ‘USER’
- function_name = 'mbdtire::USER_FIALA'
- RLENX and RLENY in [PARAMETER] block