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[pashazanousi]

I simulated aircraft landing gear to analyze touchdown effects on tire temperature. The problem is that the tire deformation is ridiculously high, and it also seems that the wheel has locked and didn't rotate.

[Aniket]

shouldn't the translation Z fixed and rotation Z free for ground to rim contact?

-Aniket

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[pashazanousi]

Thanks. You're right; I noticed that after creating the post, but my problem is not that. The deformation is due to inflation pressure. The inflation pressure expands the tire made up of hyperelastic material (Moony-Rivilin, two parameters). I tried to simulate the model with three steps. I applied inflation pressure without other loads, including gravity, in the first step. The time integration option is turned off in this step. In step 2, a constant displacement is used to generate the initial velocity for 3rd step. Same as the previous step, the time integration is turned off. In 3rd step, gravity would be applied, and the time integration would be turned on. Theoretically, this approach would lead to the desired solution, but still, the problems exist, and in 1st step, the solving process encounter error due to high deformation. It was worth saying that the reinforced belt was added to the tire to improve material strength, but it didn't work. 
I acknowledge that it is possible that the material may not be proper to bear the inflation pressure (215 psi=1.482e6 pa) and bring about high tire expansion. But how could they use this material to model aircraft tire touch-down in the following Paper?
https://arc.aiaa.org/doi/10.2514/1.C033916
Thanks for your energy and time consuming

[pashazanousi]

 

I modified my model and finally got the result. Firstly I changed tire material properties(10x), used four remote points and applied mass point in the body remote point instead of the body part. I got an acceptable result, but it differed from the paper’s result and was predictable because of the material difference.
For the next step, I added temp DOF to simulate heat generation due to friction between the Tire and runway. I add some commands to items as follows:
Tire ,Rim, and Runway parts:
et,matid,226,11
Frictional contact between Tire (contat) and Runway (Target):
keyopt,cid,1,1
rmodif,cid,18,0.1
keyopt,cid,10,2
Bonded contact between Tire and Rim:
keyopt,cid,10,2
I didn’t encounter any error, but the temperature is ridiculously high, and I don’t have any idea about that. Temperature increases quickly after the Tire touches the runway from 22 to above 3000 Celcius degrees. Even there are negative temperatures less than -3000. I’m really confused. Can anyone help?

 

[Rahul Kumbhar]

Hi,

Please check if the guidelines to set the step size helps to resolve the issue.

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v232/en/wb_sim/ds_guidelines_int_time.html

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Guidelines for Posting on Ansys Learning Forum