Tires Entity error - "Illegal index TRAC" - vehicle modeling

Question

I got this error after I changed the .tir file that is referenced by the Tires entity.

"Illegal index TRAC

Error resolving reference Event Type-value under Model-Tires-Tires-left-Tire Properties. "

I tried to switch back to the default .tir file that was loaded in the template, but the error is persisting. Not sure how do debug this since I cannot find "Event Type" under the Tires system.

For reference, I am using the FSAE Template and following the Shimable Suspension Tutorial.

Thanks!

Christopher_Fadanelli · Answer

Hi @UnfairAdvantage ,

Thank you for sharing the model.

Regarding the additional setup, I suggest going back and confirming that everything has been configured correctly. The reason for this is that the log file shows 20 redundant constraints.

Redundant constraints can impact the overall kinematics and the forces being registered at the joints.

I also noticed that the spring rate in your K&C analysis is set very high.

When running the K&C analysis, I recommend implementing the correct spring rate. For additional context, during a K&C event, the AutoTires are replaced by a single spring element whose properties are determined by the SLR and spring rate values defined in the axle parameters.

Regarding the tire file issue, I would not recommend saving the tire file in the installation directory. Instead, please save it to a local working directory and update the file path accordingly.

To replicate the issue you are experiencing, we would need access to the tire file. If the file contains confidential information, I can send you a FileDrop link via email. You can then share the file directly with me, and no one else will have access to it.

Best,

Christopher Fadanelli

UnfairAdvantage · Answer

I attached a Save-As from about 1 week before I updated the tire file. I can also share the most up-to-date model from after the issue started, if that helps. The tire file is external, but I pasted it into the installation directory along with the included ones. I cannot share the tire file but let me know if there's anything you'd like to know about it.

KinematicsV1.mdl

Christopher_Fadanelli · Answer

Hi @UnfairAdvantage ,

Can you please share the archive model before the tire was updated (File > Export > Model > Archive Model). Which software version are you using? Is the tire file from the installation directory or yours? Could you please share that file as well?

Best,

Christopher Fadanelli