Question about local equalDOF

[dynaforce]

Hi everyone,

I want to model eccentric steel brace frame.
This model is 2D one story - one bay Frame and shape of brace is inverted V with 2 metre eccentric
I try to use 'zero length Element' and 'equalDOF' for hysteretic behavior of Bracing

I have a question :

I think that 'equalDOF' affect global DOF.
How to use 'local equal DOF' (constrain).
I want to constrict 2,3 dof.

Bracing is must applied only axial force(local x-direction)

Thanks for Your Help.

[fmk]

equalDOF does effect the global DOF and I have not a clue how you are planning on modeling the system so I cannot advise you on what to do based on what you have provided.

[dynaforce]

Thank you for your response.

I want to model eccentric steel brace frame.
This model is one story - one bay Frame and shape of brace is inverted V with 2 metre eccentric :
---[1]---0----[2]----0---[3]---
|+++++/++++++++++\+++++|
|++++/++++++++++++\++++|
|++[4]+++++++++++++[5]++|
|++/++++++++++++++++\++|
|+/++++++++++++++++++\+|
|/++++++++++++++++++++\|
Applied load is only gravity load.

This is Bracing (zerolengthelement is inserted at end of bracing) :
0------[4]------0

so, I must use equal DOF. and I want that Bracing is applied local force (Compression or tensile force)

0------[4]------0 The applied local force direction at bracing : --> or <-- or ^ or V

So, I want to free to deform localDOF in -dir 1

Thanks for Your Help.

[fmk]

still don't understand what is is you want .. you want dublicate nodes where brace meets the beam and constrain the node from the brace to the node at the beam in dir 1 and 2, but not in 3 .. if do for each end of the brace it will have 0 moment at the ends.

[Mohammadf]

hi dear dynaforce
you can make a section with aggregator command in longitudinal direction and high stiffness in other directions and add to your end brace with a zerolenthsection command.

[dynaforce]

thank you for your response. Mohammadf.
then... What should I do? equal DOF for zerolengthsection command??
ex) equal DOF 2 3 ??