Defining vertical stiffness and damping for fiala tire model

I am working on a simulink model that requires computing the vertical/normal force on tire for a range of tire vertical stiffness and damping. I see option to set those parameter values for the MF tire model, but not for fiala tire model. Is there a way to define those parameters for fiala tire model? I see the mapped vertical stiffness and damping option but I'm not sure about the parameters like vertical deflection breakpoints and vertical velocity breakpoints. I need to set single value for each of the two parameters.

Answer 1

[Abhaya]

Hi Shishir,

The Simulink ‘Fiala Wheel 2DOF’ block is designed as a simplified tire with capabilities for lateral and longitudinal slip. If your model involves extensive nonlinear combinations of lateral and slip dynamics, you can use the Simulink ‘Combined Slip Wheel 2DOF’ block.

The vertical stiffness of a wheel can be expressed as a function of sidewall deflection and pressure, while the vertical damping can be expressed as a function of sidewall velocity and pressure. To incorporate vertical stiffness and vertical damping in the Simulink Fiala wheel, follow these steps:

• Open the ‘Block Parameters’ menu for the Simulink Fiala wheel 2DOF block.
• Set the ‘Vertical Motion’ option to ‘Mapped stiffness and damping’.
• In the ‘Vertical’ section, set the appropriate breakpoints for deflection, pressure, and velocity. To set a single value for vertical stiffness and vertical damping, assign all values for force due to deflection and force due to velocity to the constant value.

For more information about fiala wheel, follow the MATLAB documentation for Simulink ‘Fiala Wheel 2DOF' block.

https://www.mathworks.com/help/releases/R2021b/vdynblks/ref/fialawheel2dof.html

Please refer to the latest version of the MATLAB documentation for ‘Fiala Wheel 2DOF' block.

https://www.mathworks.com/help/vdynblks/ref/fialawheel2dof.html

Hope this solves your query.