Quasi-static crushing and displacement based BC

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Quasi-static crushing and displacement based BC

Abaqus Users mailing list
Hello Dear Friends,
 I am doing explicit (with mass scaling) crushing analysis of porous media with small dimensions as 50 mm approx in all directions. Displacement BC with tabular data was given.
 And I read the reaction force from the impactor surface that is a rigid plate. I applied mass-scaling with caution; no problem on energy levels.
 

 However, I encountered loss of the surface contact between the rigid impactor and crushed material. Here:
 http://imgur.com/a/NKZU4 http://imgur.com/a/NKZU4

 Interestingly, crushing was continued but due to the loss of contact, I could not read the reaction force properly.
 Is there any advice on it?
 

 

 Regards
 

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RE: Quasi-static crushing and displacement basedBC

Abaqus Users mailing list
Presumably the momentum of the foam structure causes it to keep moving even after the indenter stops.  How is the model constrained on the opposite side of the structure?  Can you retrieve reaction forces there?

Regards,

Dave Lindeman
Lead Research Specialist
SEMS Research Laboratory
3M Center 235-3G-08
St. Paul, MN 55144
651-733-6383

From: [hidden email] [mailto:[hidden email]]
Sent: Thursday, June 15, 2017 6:07 AM
To: [hidden email]
Subject: [EXTERNAL] [Abaqus] Quasi-static crushing and displacement based BC



Hello Dear Friends,

I am doing explicit (with mass scaling) crushing analysis of porous media with small dimensions as 50 mm approx in all directions. Displacement BC with tabular data was given.

And I read the reaction force from the impactor surface that is a rigid plate. I applied mass-scaling with caution; no problem on energy levels.



However, I encountered loss of the surface contact between the rigid impactor and crushed material. Here:

http://imgur.com/a/NKZU4

Interestingly, crushing was continued but due to the loss of contact, I could not read the reaction force properly.

Is there any advice on it?





Regards







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Re: Quasi-static crushing and displacement basedBC

Abaqus Users mailing list
One other thing to back up Dave's comment.  Take a look at the magnitude of

the acceleration fields in that region.  If those are non-zero then you
have forces still acting on it due to inertia.  If that's the case, then
your part left the surface and is flying towards the bottom plate (out of
frame).  You could probably go through the stress-equilibrium equations to
back out the elemental acceleration (typically a derived nodal value) and
determine the force in the elements.  S(ij,j)=mAj.  I frequently do this to
confirm if an input pulse in a dynamic simulation is being transmitted
correctly through the material.


What kind of interaction properties do you specify between the top platen
and the sample?  Perhaps a cohesive bonding to the plate would help using
infinitely high debonding parameters.


Kindly,


Steve


On Fri, Jun 16, 2017 at 9:40 AM, David Lindeman [hidden email]
[Abaqus] <[hidden email]> wrote:


>
>
> Presumably the momentum of the foam structure causes it to keep moving
> even after the indenter stops. How is the model constrained on the opposite
> side of the structure? Can you retrieve reaction forces there?
>
> Regards,
>
> Dave Lindeman
> Lead Research Specialist
> SEMS Research Laboratory
> 3M Center 235-3G-08
> St. Paul, MN 55144
> 651-733-6383 <(651)%20733-6383>
>
> From: [hidden email] [mailto:[hidden email]]
> Sent: Thursday, June 15, 2017 6:07 AM

> To: [hidden email]
> Subject: [EXTERNAL] [Abaqus] Quasi-static crushing and displacement based
> BC
>
> Hello Dear Friends,
>
> I am doing explicit (with mass scaling) crushing analysis of porous media
> with small dimensions as 50 mm approx in all directions. Displacement BC
> with tabular data was given.
>
> And I read the reaction force from the impactor surface that is a rigid
> plate. I applied mass-scaling with caution; no problem on energy levels.
>
> However, I encountered loss of the surface contact between the rigid
> impactor and crushed material. Here:
>
> http://imgur.com/a/NKZU4
>
> Interestingly, crushing was continued but due to the loss of contact, I
> could not read the reaction force properly.
>
> Is there any advice on it?
>
> Regards
>
> 3M security scanners have not detected any malicious content in this
> message.
> Click here<https://spam.mmm.com:443/pem/pages/digestProcess/
> digestProcess.jsf?content=aedaaa864ecbae94822c5bddc397d2
> 0bb65829d1436ed1d81160cc4cca01e5afe8a0bf42417d2029b270cb234e
> 90b84351d6ab17c03eb54bd8718a676765231fe413d2baa605aa8c2795c6
> 07a6104600f81ff13c996438e24a8f5f321526c5cb0422efed7cc58c82ca
> abd3850ed77591b5d3de2338537e82daec08a0f6de46906c9ed584b5d10938> to report
> this email as spam
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