Rubber/Asphalt contact parameters in MSC Adams
Rubber/Asphalt contact parameters in MSC Adams
(OP)
Hello dear colleagues,
I am trying to simulate a platform with 4 wheels in MSC Adams.
My question is about the contact parameters I need to defines to simulate rubber/asphalt contact between tires and a ground plate.
The parameters required are:
Stiffness, damping, static friction, and dynamic friction.
Can you help me to choose their values?
Thank you.
I am trying to simulate a platform with 4 wheels in MSC Adams.
My question is about the contact parameters I need to defines to simulate rubber/asphalt contact between tires and a ground plate.
The parameters required are:
Stiffness, damping, static friction, and dynamic friction.
Can you help me to choose their values?
Thank you.





RE: Rubber/Asphalt contact parameters in MSC Adams
should get you started
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
When I set the damping to 0, the vehicle just fall of the road, I mean as if there's no contact but, when I increased it the model worked as expected.
What does it mean physically that the damping of the contact is zero?
RE: Rubber/Asphalt contact parameters in MSC Adams
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
No, I do cars.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
Isn't restitution better for simulating a tire that bounces several time? or it can be simulated using both impact or restitution by changing the parameters?
The alternative to simulating the contact using the parameters you provided me, is to use adams/tire. would it make a lot of difference?
And if it does, what resources would you recommend me to learn adams/tire from?
I need some examples, I found resources but, I am not satisfied about the level of knowledge I acquired from them.
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
ADAMS being ADAMS you may need a bit of friction in there just to stabilise the model, but you just have to try it with and without.
I don't actually model a tire like that, I use /Tire. I'm not really aware of any great guides to using /Tire, between Pacejka's book and the manual and help it seems OK to me.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
I turned to use A/Tire according to your advice.
Now I need 4 wheels for the robotic vehicle I am modeling, the 2 front wheels are different in diameter from the 2 back wheels.
How can I build custom tires using A/Tire?
I used only the available tires and roads in tires.tbl and roads.tbl folders.
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
I used only uat.tir and 2d_flat.rtf, this was during learning about the tie/road tool in Adams. I don't have previous experience with vehicle dynamics but with robots.
You can recommend me a customizable tire based on my described situation: (I need it customizable to use 2 pairs, each of different diameter)
The situation I want to simulate is a robot that transforms into a vehicle, I want to simulate it while going on a straight road to find the critical acceleration at which tipping will happen in the longitudinal direction. In Adams I firstly used torus as a tire, with solid-solid contact and asked here about the contact parameters and you replied me. The front wheels bounce when they touch the road, and the results are not satisfactory.
The 2nd situation is while turning, to determine the critical speed at which the centrifugal force will cause tipping also but in the lateral direction.
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
I already find a way, I edited Fiala tire and the 2d_flat road to fit my model.
I will edit uat.tir now according to your advice.
How can I decide to use uat.tir or fiala or any model?
and according to my forementioned robotic vehicle case, what is the tire that fits this situation?
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
I started with the Adams/tire module,
I got these ERORRS when I tried to simulate the model after ading tires:
ERROR: Standard exception "There is no solver license!" caught in file L:/source/adamscxx/src/Asol/slv_intr.cxx, line 1618
ERROR: No model has been defined. Check for successful reading of the model before operating on a model.
My concern is about the 1st error, it means what?
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
Now, I need to measure the critical turning velocity, this means that I need a road with a turn in ADAMS.
I tried polyline in ADAMS but it says that the road will not appear graphically.
My questions are:
1.Is there a polyline that can be shown even after some modifiv=cation? there are polyline, polyline_1, polyline_3
2.How can I deal with a road that i can't see?
3. What is the standard radius of a curved road if I am going to build a curved road in ADAMS?
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.
RE: Rubber/Asphalt contact parameters in MSC Adams
There is no standard curve, skidpans are often 30 to 60m radius.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Rubber/Asphalt contact parameters in MSC Adams
RE: Rubber/Asphalt contact parameters in MSC Adams
I am facing a problem in the model I attached (made with ADAMS 2014) it is just a very simple vehicle with 4 wheels. I applied motion (as velocity) of 40d/s on the backward right wheel, and 0d/s on the backward left wheel.
I expected that the model will turn in a circumference of a narrow circle having its center at the left wheel (of velocity zero) but, the model just goes in a wider circle as if there is a motion applied on the left wheel. What is th reason of this?
I attached the .cmd file but changes .cmd to .txt so, please make it .cmd again to open with ADAMS.
Regards,
Mohamed Salaheldin
Mechatronics and Robotics research student.
Egypt-Japan University of Science and Technology.