Boundary conditions Abaqus

[SarahMatta]

Good morning everyone,

I was wondering if there is a way to force two nodes to have the same displacements without giving them values of these displacements.

I'm going to explain with more details: i am working on a cellular material (foam with open cells), so i've modelized one cell of it (Kelvin cell) and i am doing the boundary conditions so some nodes should have identical boundary conditions (because when i assemble many cells together, some nodes connected should have the same displacements. The question is: how could i make similar displacements for two nodes without giving these displacements a particular value.

Thank you in advance,

Sarah

 

[IceBreakerSours]

Look for *Equation in the documentation. Out of the available options, this card will give you the most flexibility.

Are you new to this forum? If so, please read these FAQ:

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[DrBwts]

Sorry but your question is not very clear. Are you asking about Periodic Boundary Conditions for your cell?

 

[SarahMatta]

Sorry for being not clear, yes it is exactly this

 

[SarahMatta]

Hello,

I am sorry for disturbing you again, i want to use the option of equation constraint to do the periodicity in my kelvin cell, equations should be:

1)Ui1 - Ui2 = Ui1(ref) - Ui2(ref) with i=1,2,3 (Uij(ref) are displacements of conjuguate points)
2)Oi1 - Oi2 = 0 with i=1,2,3 (O is theta the rotation)

but how can i introduce these equations in the equation constraints in Abaqus? can someone please tell me the steps i should do? (i've seen this part in the abaqus tutorial but still don't know how to do it)

thank you in advance

sarah

 

[IceBreakerSours]

Always google before you ask.

Search for Applying Periodic Boundary Conditions in Finite Element Analysis in the PDF. There is more content available online, just in case you require additional help.