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Foam Compression

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Posts: 6
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Joined: 1 year ago

Greetings Guys,

For my crush model setup, one of the material I have been using is Fuchang Foam to model a material that absorbs energy, but as soon as the low speed crush starts, within the first few milliseconds I get the error of negative volume from the foam and the simulation stops. I cannot fidget with the material curve of the foam, as It would not capture the right property. the erode option is also =1. How do I get past this problem?


Thanks in advance! 

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Negative Volume
Posts: 626
Joined: 5 years ago

Hi @kein_roboter

When you say erode=1, what card is that in? Because I didn't think fu chang foam had that option. 

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Joined: 1 year ago

Posts: 6

Hello @negativevolume, thanks for the reply. Sorry for not being to clear with my doubt. I am trying to modell a crushing of lithoum ion cells, which has a foam in between the cells with material - fu chnag foam assigned with thickness of 2.23 mm. and the thickness of neighbouring cells is 11.46 mm. Both the sides of the foam are in contact via tied nodes to surface (nodes et form the foam surface and segment set from the cell surface). When I proceed with tthe simulation, after too much compression, the run ends with negative volume error.

Hence, to counteract this problem I set in control time step, in control termination the values of dtmin was set to 0.05 (a non-zero value) and in control time step erode was set to 1. but the eroded particles had no contact with neighbouring cells. But the enreges were stable with positive sliding interface energies. Now I added the eroding single surface contact and found more instabilities in the module.


Is my approach right or am I making a mistake here? 


Thanks in advance.