Contact between distant bodies

[samv1900]

Hello there:

I am reltively new to Abaqus, but have done almost all my homework before posting this one.

Is anyone aware if Abaqus standard can be used to simulate contact between objects that are initially seperated by a finite distance. Or is it that this can only be solved using abaqus explicit?

Thank you in advance.

Sam

 

[DanStro]

I am also still relatively new to Abaqus but I think the normal procedure is to create a separate step that takes over when the parts come into contact. That way you can deactivate the contact controls for the step where the parts are not in contact.

 

[rstupplebeen]

This can be done in standard. Just set up the contact interaction. When using contact rigid body motion is often an issue. Make sure that all 6 DOF are constrained or turn on stabilization to provide damping. Hope this helps.

Rob

 

[samv1900]

Hello Rob and DanStro:

Thank you for your precious time.

I tried a lot, but just can't get a part to push the other.

I cannot change the initial position of the parts. But, besides that I just need to push any part to get the other to realise contact and then be displaced!
Have posted my file here:

http://files.engineering.com/getfil...48-b553-bdcfd18086f6&file=dec22_real_case.cae

Please can you glance thru to see where the mistake is?

Thank you a bunch!
Sam

 

[rstupplebeen]

Sam,

Cool geometry. Depending on what you are planning in this analysis I think standard would be more appropriate. You have an amplitude of:
0,1
1,8
I think that
0,0
1,8
would be more appropriate but that would be the default if you didn't specify. I believe that a tied constraint may be closer to reality. Hope this helps.

Rob

 

[samv1900]

Thanks, Rob.

I am still struggling to get the other parts to move an realise contact since they are not initially in contact.

will try and keep you posted!

Thank you so much.

Sam!

 

[samv1900]

Hello again:

I somehhow cannot get the parts to realise contact in Abaqus standard or explicit.

I either see the objects moving into each other or get locked and not move anywhere or move in the opposite direction of the specified velocity.

Any help would be of great help. plz find my file above.

Thanks

Sam

 

[samv1900]

Problem solved !

1. Abaqus has a hard time to simulate contact invlocing rigid bodies. If you can make really hard deformables then perform the analysis.

2. missing element property: create a set for the elements, then designate property.

Thank to all you guys and John!

Regards
Sam

 

[corus]

Rigid bodies tend to perform better in contact, in my view, than normal elements. In your case though I'd reconsider your contact behaviour as you've used general contact when two seperate contact surfaces may have been better. I'd also review all your boundary conditions on your rigid bodies as you don't seem to have sufficient restraints. Explicit will still run the analysis with insufficient restraints, whilst standard will prevent it. I'd also change your element types from 3 noded shell elements to six noded triangular elements as the results from 3 noded elements are pretty much useless. Should they be shell elements or solid elements, by the way?

corus