## internal hinges in Opensees?

Forum for OpenSees users to post questions, comments, etc. on the use of the OpenSees interpreter, OpenSees.exe

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RajArora
Posts: 8
Joined: Mon Oct 19, 2020 5:39 am

### internal hinges in Opensees?

how to incorporate internal hinges in a beam at any location.?
Is there a command for that?
or with the help of zero-length element then how to assign moment 0 at that point
We cannot assign in the restraint condition because that will make total moment 0 at that point but in the case of plastic hinges moment from both sides are zero
So please tell me how to take internal hinges in OpenSees

mhscott
Posts: 586
Joined: Tue Jul 06, 2004 3:38 pm
Location: Corvallis, Oregon USA
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### Re: internal hinges in Opensees?

Define two nodes at that point then use equalDOF on the translational DOFs to make a moment hinge.

RajArora
Posts: 8
Joined: Mon Oct 19, 2020 5:39 am

### Re: internal hinges in Opensees?

but Scott at internal hinge moment from both sides is 0 where you are considering that

mhscott
Posts: 586
Joined: Tue Jul 06, 2004 3:38 pm
Location: Corvallis, Oregon USA
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### Re: internal hinges in Opensees?

I'm not sure what else you mean by internal hinge then.

RajArora
Posts: 8
Joined: Mon Oct 19, 2020 5:39 am

### Re: internal hinges in Opensees?

Internal hinges are provided in a structure to reduce the statical indeterminacy of the structure.
The bending moment at the internal hinge is always zero from either side. An internal hinge makes the structure more flexible.
It allows the structure to move which reduces the reactive stresses.
As far this is the most suitable definition of the internal hinge.

mhscott
Posts: 586
Joined: Tue Jul 06, 2004 3:38 pm
Location: Corvallis, Oregon USA
Contact:

### Re: internal hinges in Opensees?

Then my original answer is what you want. Define two nodes, break up the element, and define equalDOF (translations equal, rotations not equal) on the two nodes.