Impact Conservation of Momentum

Elmer cases by the users for the users
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kevinarden
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Impact Conservation of Momentum

Post by kevinarden » 11 Mar 2020, 20:11

Check conservation of Momentum for impact of two bodies using contact surfaces.
Body one is accelerated to a velocity of 8 using a force then impacts into body 2 transferring all momentum into body 2 accelerating it to a velocity of 8. Impact, conservation of momentum, and contact confirmed.
Validation:
impact.pdf
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Link to Video and Case:
https://github.com/mrkearden/impact
Case files:
impact.zip
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Time history of Blocks:
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raback
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Re: Impact Conservation of Momentum

Post by raback » 11 Mar 2020, 23:19

Hi Kevin,

This is really great small case! I'm not even sure whether the contact machinery was much tested for this kind of impact simulations at all. The emphasis was on finding steady state contact solution. Of course one hopes that 1+1=2 but you can never be sure before you try out the combination. It is great that momentum is conserved. Thanx!

-Peter

kevinarden
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Re: Impact Conservation of Momentum

Post by kevinarden » 11 Mar 2020, 23:52

I was trying to do a much more complicated impact case, but when the results did not look right, I fell back to something much more fundamental. Even in this fundamental case I had to redo it many times to get the model correct. It is important to get all of the inputs correct, and have the right mesh size, time steps, etc. This case confirms it is not he software, but the user that needs refinement.

kevinarden
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Re: Impact Conservation of Momentum

Post by kevinarden » 12 Mar 2020, 12:07

https://github.com/mrkearden/impact

I added an impact2 case to the git hub.
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impact.png
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