Release of ADAMS PAC2002 Tire Datasets - FSAE TTC - Stackpole Engineering

[M Stackpole]

TTC Members,

Stackpole Engineering Services Inc. is pleased to announce that we have completed and distributed a full set of ADAMS/2005r2 PAC2002 tire datasets, which were created from the raw data measured from Rounds 1-3 of the TTC tire testing at Calspan. The distribution includes a total of 20 *.tir files for the following tires :

Avon 6.2/20-13 FITO 9241 Formula SAE Tire @ 12 psi, 6 inch rim
Avon 7.2/20-13 HDTO 9760 Formula SAE Tire @ 12 psi, 6 inch rim
Hoosier 20.0x7.5-13 Road Racing 43161 Formula SAE Tire @ 12 psi, 7 inch rim
Hoosier 20.0x7.5-13 Road Racing 43161 Formula SAE Tire @ 12 psi, 8 inch rim
Hoosier 20.5x7.0-13 Road Racing 43129 Formula SAE Tire @ 12 psi, 6 inch rim
Hoosier 20.5x7.0-13 Road Racing 43129 Formula SAE Tire @ 12 psi, 7 inch rim
Hoosier 20.5x7.0-13 Road Racing 43129 Formula SAE Tire @ 12 psi, 8 inch rim
Hoosier 18.0x6.0-10 Road Racing 43101 Formula SAE Tier @ 12 psi, 6 inch rim
Hoosier 20.0x6.0-13 Road Racing 43131 Formula SAE Tire @ 12 psi, 6 inch rim
Hoosier 20.0x7.0-13 Road Racing 43157 Formula SAE Tire @ 12 psi, 6 inch rim
Hoosier 20.5x6.0-13 Road Racing 43128 Formula SAE Tire @ 12 psi, 6 inch rim
Hoosier 20.5x7.0-13 Road Racing 43129 Formula SAE Tire @ 12 psi, 6 inch rim
Goodyear 20.0x7.0-13 Eagle D2692 Formula SAE Tire @ 12 psi, 6 inch rim
Goodyear 20.0x7.0-13 Eagle D2692 Formula SAE Tire @ 12 psi, 7 inch rim
Goodyear 20.0x7.0-13 Eagle D2692 Formula SAE Tire @ 12 psi, 8 inch rim
Goodyear 20.0x7.0-13 Eagle Special Radial D2509 Formula SAE Tire @ 12 psi, 6 inch rim
Goodyear 20.0x7.0-13 Eagle Special Radial D1385 Formula SAE Tire @ 12 psi, 6 inch rim
Goodyear 18.0x6.5-10 Eagle Special Radial D1383 Formula SAE Tire @ 12 psi, 6 inch rim
Michelin 16/25-13 Radial X F146045 Formula SAE Tire @ 12 psi, 7 inch rim
Michelin 16/25-13 Radial X F146045 Formula SAE Tire @ 12 psi, 8 inch rim

Our engineers have tested each dataset in ADAMS/Car and were able to validate that the simulations completed properly and the tire model reacted as expected. Several notes regarding the tire datasets :

1. PAC2002 tire model coefficients were fit using the SES Inc proprietary in-house fitting program, which is routinely used to developed tire modeling coefficients for a wide array of OEM, Racing and Military customers. Every effort was taken to ensure accurate fits to the raw data within the mathematical capabilities of the PAC2002 equations. In some cases, compromises were required to ensure the "best"� fit possible for the range of testing conditions. This is typical of any tire data fitting program.

2. As specified in the ADAMS tire datasets, the units for the coefficients and required inputs are : Vertical Load (N), Slip Angle (rad), Inclination Angle (rad) ,Slip Ratio (-), Unloaded Radius (m), Springrate (N/m), Nominal Load (N)

3. The tire model "use_mode"� has been set in each dataset according to the amount of data available for the specific tire. For example, for tires that had no drive/brake data available, the "use_mode"� was set to 2.0. For tires where drive/brake data was available, but combined was not, the "use_mode"� was set to 3.0. Finally, for tires where drive/brake and combined data was available, the "use_mode"� was set to 4.0.

4. Although datasets have been created for the Goodyear D1383 and Hoosier 43101 (set to "use_mode"� = 2.0), they will not run in certain ADAMS pre-canned events due to the fact that there are no longitudinal coefficients, and therefore the model is not able to generate drive/brake forces.

5. The tire data was fit in the ADAMS required ISO Metric coordinate system.

6. Static rates for each tire were determined from Calspan test summary sheets and represent an average springrate of the tire.

To further assist in the application and analysis of the PAC2002 tire datasets, SES Inc has created a summary report which provides a detailed listing of the individual Pacejka 2002 tire coefficients, and a complete listing of the equations used for the fitting process.

The employees at Stackpole Engineering Services sincerely hope that these PAC2002 ADAMS tire datasets will be a useful tool in your engineering and modeling process. We wish you the best of luck in the upcoming competition. If you have any questions, comments, or need any technical support, please feel free to contact me at any time. If your school is part of the TTC and did not receive a copy of the ADAMS tire datasets and the SES report, please contact me and I will forward the information along.

Sincerely,

Mike

Michael J. Stackpole, President
Stackpole Engineering Services, Inc.
1375 South Main Street, Suite 201
North Canton, Ohio 44720
mstackpole@stackpoleengineering.com | (330) 244-9110 Office | (330) 418-9847 Cell

[Altair]

Hi,

First of all thank you for providing us with such important data.
But I had a problem. When I try to incorporate the tir files into my adams assembly. The tires appear to small. I mean they are dimensionally wrong which is visible.

[Joe_Little]

Just out of curiosity, how/why two sets of data with no longitudinal coefficients? If you don't something in there, I don't see how it solves any event (though admittedly I've never tried it!)

Also, fairly sure none of the coefficients you've fitted using the 2005r1 PAC02 standards will have been deprecated, making these compatible with anything up to the latest version of Adams (2012), which I recommend because of the new database updates. I can test this if you want.

Thanks for the contribution guys, and email me if you ever need help on our side.

[Crispy]

The two sets without longitudinal coefficients are 10" tires. Vertical travel limitations of the tire testing machine prevented longitudinal testing of 10" tires in the early rounds. In order to perform tests with the smaller tires, an adapter was used that allowed the lateral tests to be performed. But, with the adapter, the test machine could not drive/brake the tires.

One solution to this problem is to take the longitudinal coefficients from another, possibly similar tire, and plug them in. It's not going to be right, but it will be something...

Several 10" tires were fully tested in the round 5, but as far as I know, Stackpole has not provided models since round 3.

As for Altair's issue of the tires being too small, just a guess, but you might need to adjust due to units? I believe the tire dimensions in the Stackpole models are the radius measured in meters.

[wagemd]

Out of curiosity, are rounds 4-5 in the queue for sometime in the future?

Thank you for everything you have already contributed!