Tension only bracing

[Muntasir]

Hi,
Is it possible to model tension only bracing in seismostruct?
If possible then how can i model it?

Thanks

[seismosoft]

Have you searched this Forum and the Help System for the word "tension"? We are sure you will find some hints on the matter.

Seismosoft Support

[Muntasir]

Hi,
Thanks for the response. I found some guidelines to model tension only bracing in the forum. But surprisingly it behaves as a tension only bracing in static pushover analysis but not in time history analysis. In dynamic TH analysis it takes both tension and compression.
Can any one suggest me what to do?

Thanks

[ricardomonteiro]

Hi Muntasir,
According to your description, the problem seems to have come up with the loading inversion along time, which happens when you go from pushover to time-history analysis. Which type of link element have you used? Gap-hook? Lin_asm? Have you checked if your link is correctly defined so as to accommodate such behaviour? I would say the solution would be there.
Ricardo

[Muntasir]

Hi Ricardo,
Thanks for the answer. I have used a link element (lin_sym) with very low rotational stiffness. I have also tried with bil_asm link element.
But in both cases it behaves as tension only bracing in pushover analysis but not in TH analysis. Can you tell me what type of link I should use?

Thanks

[kalmithkush]

Hi Muntasir,
Try in this way that you can model the brace with high slenderness value to have very low resistance in compression. In this case, you have to model a brace with two inelastic forced-based elements. In addition, you have to give an initial imperfection at the mid node to initiate the buckling of the brace. Brace length/300 will be a reasonable value for the imperfection. If you need further assistance, please let us know.
best regards,
Kushan

[Muntasir]

Hi Kush,
Thanks for your reply. I tried in that way you suggested. But The result is same. Its not working. Can you suggest me what to do or can you please send me any sample model if you have done so.

Thanks

[kalmithkush]

Hi Muntarsir,
Could you please send your new model?
Kushan

[Muntasir]

Hi Kush,
I sent my model to u long ago. Did u have a chance to look at that?

Thanks

[seismosoft]

Upol, hi.

Please send us your initial model (with link elements), and we will immediately have a look at it.

Thanks.

Seismosoft Support