MSC Adams Tire slipping

[BlazPlestenjak]

Hi!

I am working with MSC Adams software. I have built a Formula Student model, which works fine, the only issue that i have is that contact between tires and road seems to not be correct. When I apply torque to the rear axis, the tire seems to slip way to much and I don't know how to correct this. Torque which I am appling should not make the tire slip (200Nm of torque, radius of tire is 200mm, which means force of 1000N). Tire is under load of 750N. Friction between road and tire is set at 2.0 (Umin), but even if I change it to 10 it doesnt really make difference. Tire should not slip in this conditions, but it does.

Can someone help regarding this? I am appending files of road and tire.

https://files.engineering.com/getfi...1a9-4d83-aaa9-4f54e8eff009&file=Hoosier_1.tir

https://files.engineering.com/getfi...-fa8e-4230-8d49-e4e6ecdd8506&file=3d_flat.rdf

Thank you

 

[GregLocock]

can you run the quasi static event straight line braking, 0-2g, and plot Fz at the contact patch vs ax?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[BlazPlestenjak]

So,

I have made a quick straight event. As you can see, during acceleration weight moves backwards and during breaking fowards. At all time there is weight under the tire, but when I apply torque to the rear axle it still slips (It still pushes the car foward, but the wheel is spinning more than it should and the acceleration is not as high as it should be). I think the problem is in tire file. When I change the tire, it slips even more. I have now change CSLIP to higher number, which made issue a little bit better, but not as it should be.

https://files.engineering.com/getfi...1-bb3f-4762-bcbd-e89de650d213&file=export.tab

https://files.engineering.com/getfi...87a-4d62-9751-711e38ddfe12&file=Hoosier_1.tir

 

[GregLocock]

And is that not what you'd expect?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[BlazPlestenjak]

The shape of the graph is what I expecr, but wheel should not loose grip at a very small torque. In my case any torque that I apply to the wheel there is some kind of slip.

 

[GregLocock]

I agree, but you haven't given me much to go on.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[BlazPlestenjak]

Would you help me if I attach additional data? What exactly would you need?

 

[GregLocock]

So in the brake test look at Fx at each CP, and the slip velocity. From your plot it all looks as though it is working properly.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?