Predefined velocity field without stress? 2

[CivetCat]

I stress my object with predefined velocity field. I just want my object moving at uniform velocity without any stress field. Sorry for the dumb question. Thanks in advance.

 

[CivetCat]

I also want to add that when I set 'Rigid body' constraint on object. The object doesn't even move. I don't really understand. Thanks a lot.

 

[CivetCat]

Can someone answer this simple question please? I am desperate for help. Thanks in advance.

 

[rstupplebeen]

If you explain what you are trying to do, post pictures or models you will get more help.

Rob Stupplebeen

 

[CivetCat]

I created a 2D deformable solid circle. I meshed it. I assigned material. I created a velocity field to get it moving. Then the result was that the circle is stressed. I think the stress is from the individual elements moving and interacting with each other. I just want the whole body moving without stress. Thanks in advance.

 

[akabarten]

Hi,

To do this You need to model your circle plate as rigid body and next assign velocity only to reference node of the body.
Only reference node of rigid body has a degrees of freedom other nodes has no DOF.

1. Go to interaction module
2. Create reference point (Tools -> Reference Point)
3. Define rigid body (Constraint -> Create -> Type: Rigid Body)
4. Add elements and the reference point

Reagrds,
akaBarten

 

[CivetCat]

Dear akaBarten,

Thank you very much. Your help is appreciated. If I'd to maintain the body deformable so as to analyse the stress involved in contact with another body, what should be the constraint? I tried the 'tie' between reference node and the surface of type 'mesh', but the body now doesn't move at all. Attached is my actual project. Thank you very much.

Many thanks,
Thomas

 

[akabarten]

Hi Thomas,

>>> If I'd to maintain the body deformable so as to analyse the stress involved in contact with another body.

I am afraid there is no option (constraint) to do it with Abaqus. But the stresses developed during movement should be neglect compare to stresses occur in contact phase. The stresses proceeds from inertia forces during movement. So if you do not have significant acceleration these forces should be small compare to contact forces.
If you use Abaqus/Explicit you can try split analysis into two steps and use *ANNEAL keyword to set all variables to zero after movment and before contact.

Regards,
akaBarten

 

[CivetCat]

Dear akaBarten,

You cannot be more helpful. Thank you very much.

Many thanks,
Thomas