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Post by bmobashe » Mon Jul 09, 2012 11:27 am

Does anybody know how lagrang multiplier nodes work in BeamContact elements? and How I can define them?
I saw the Excavation example in OpenSees. All the lagrang multiplier nodes have the same coordinates (0,0) in 2D ,and I can not realize the concept behind that.
Thank you so much for your help.
Bahareh Mobasher,
Universityof California,Irvine

Posts: 52
Joined: Mon Jul 26, 2010 12:30 am
Location: Isfahan University of Technology

Re: BeamContact3D

Post by hadisayadpour » Fri Jul 13, 2012 8:30 pm

I have the same problem with Lagrange multiplier node. I searched the reference provided in the manual for the concept behind that but there was nothing about Lagrange multiplier node.
good luck
Hadi Sayadpour,
Isfahan University of Technology
Hadi Sayadpour
Ph.D. Candidate

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Location: sharif

Re: BeamContact3D

Post by dehnavi » Fri Aug 03, 2012 7:48 am

The method of Lagrange multipliers is used to enforce the contact constraint in the BeamContact3D element. This is not the only way in which to do this , but it is the way that was chosen by the team who implemented the element. The use of this technique requires an additional node which allows the Lagrange multiplier to be included in the system of equations. Each contact element requires a separate Lagrange multiplier node, and these nodes can be located anywhere, it doesn't matter.

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Re: BeamContact3D

Post by shivanirani11 » Thu Oct 18, 2012 9:28 pm

I am also facing the same problem, how to select the lagrangian node coordinate and how these node will help incorporating the contact condition.

Please help me.