local coordinates

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martinmasanes
Posts: 38
Joined: Thu Jun 27, 2013 2:39 pm
Location: universidad de los andes

local coordinates

Post by martinmasanes » Fri Jan 03, 2014 6:24 am

Dear fmk

I'm working with an SCBF and I want to measure the axial displacement of a brace, so the recorder I'm using is the node disp recorder, and then get the axial displacement correcting with sin() and cos(). The question is if there exist a recorder so that I can get the axial disp without correcting, or if it is the possibility to rotate de local coordinates of a node.

Thanks!!

Martin Masanés

fmk
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Re: local coordinates

Post by fmk » Fri Jan 03, 2014 10:54 am

what element are you using?

martinmasanes
Posts: 38
Joined: Thu Jun 27, 2013 2:39 pm
Location: universidad de los andes

Re: local coordinates

Post by martinmasanes » Fri Jan 03, 2014 11:18 am

The brace is a "chain" of 10 forceBeamColumn elements, like Vesna's example of SCBF.

fmk
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Re: local coordinates

Post by fmk » Fri Jan 03, 2014 1:48 pm

in that case no. if you had used a single element you may have been able to get the local axial deformation. for multiple elements you would have to add them all up, the cos and sine alternative is just as easy.

martinmasanes
Posts: 38
Joined: Thu Jun 27, 2013 2:39 pm
Location: universidad de los andes

Re: local coordinates

Post by martinmasanes » Mon Jan 06, 2014 5:52 pm

I know I should know this, but to compute the axial displacement, I shoul consider only the end nodes/elements, or is it necesary to include de inner node/elements displacements? I ask this because the braces buckle, so I have the doubt if the axial displacement (ploted in all the reports about this) is only the distance between end nodes, or it is the brace length?

sory if it is a basic question, but I really have the doubt

Thanks

Martin Masanés.

fmk
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Re: local coordinates

Post by fmk » Tue Jan 07, 2014 10:10 am

depends what you want .. the results will be different as if you include all the nodes you will be getting some contribution from the deformed shape of the element that will not be there if you just look at ends.

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