A/Car lateral tire forces during a quasi-static simulation

[Vojtech Brychta]

Hello,

I'm struggling with the tire model (pacejka2002) in A/Car. I'm running a modified tilt table analysis where the outcome of the simulation depends on lateral forces in the tire-tilt table contact. The problem is that I'd like to run the simulation as a quasi-static, not dynamic, and in that case there are no lateral (or longitudinal) forces within the tire-tilt table contact even though the tires are laterally deformed. It behaves as it should during the dynamic mode.

I tried different USE MODE in the tire data, but no effect. I noticed there is a contact lateral stiffness among the dynamic coefficients only, therefor not active during a quasi static simulation. Is there a way to run a tire in a "dynamic" mode for a quasi static simulation?

I hope I explained the problem well enough.

Thank you for the help.

Sincerely,
Vojtech

 

[GregLocock]

Sounds like a good question for Hexagon/MSC.

I don't use Pac, but I'm guessing that statically there's no slip so no grip. Bad guess, SKID_PAD is a quasi static setup, so obviously the tires grip in that. And CRC is quasi-static.

Cheers

Greg Locock


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[Vojtech Brychta]

Thanks for a quick response! I will raise the question with the MSC and let you know when I know the answer.

Vojtech

 

[Vojtech Brychta]

So after a long discussion I learned that it's just impossible. Apparently, it is due to tire relaxation although it's not clear to me how is it related to similation mode. Seems that Pacejka tire model just cannot calculation lateral/longitudinal forces in statics. So I have to create an additional force to go around this issue.

Vojtech