Pre-northridge 3-, 9- and 20-story LA buildings in SAC steel

[buddhasarah]

I modeled 3-, 9- and 20-story LA buildings in SAC steel project and performed pushover analysis using both Drain-2dx and Opensees but I found that the post yield behavior are completely different.
Element type 02 is used in Drain-2dx and steel02 is used in Opensees. Strain hardening ratios are the same and PDelta effects are taken into account in both analyses.
However, pushover curves obtained using Drain-2dx tends to go down after yielding, the post-yield slope is negative for every model buildings and the negative slope is extremely steep for the 20-story building. While the pushover curves obtained using Opensees have positive post-yield slope for every model buildings, and the post-yield slope for every model buildings are almost the same, the value of post-yield slope is roughly the same as the product of pre-yield stiffness and strain hardening ratio.
Has anybody perform the similar analyses using both Drain-2dx and Opensees? I want to know the reason of causing the significant difference of the results.
Thank you very much~~

[silvia]

is the steel material in drain bilinear, or does it have a negative slope at some point?

[buddhasarah]

The steel material in Drain-2dx is bilinear with constant post-yield slope.
The only difference is that Opensees represents the bilinearization in terms or stress-strain relationship while Drain-2dx represents in terms of moment-curvature relationship.

[pouyatirip2000]

hi buddhasarah
can i have your opensees code of the SAC model?
i am engeener in iran and i need those code .if it possible please contact me .thanks a lot.my email is :hosseinzadeh.pouya@gmail.com

buddhasarah wrote:
> I modeled 3-, 9- and 20-story LA buildings in SAC steel project and
> performed pushover analysis using both Drain-2dx and Opensees but I found
> that the post yield behavior are completely different.
> Element type 02 is used in Drain-2dx and steel02 is used in Opensees.
> Strain hardening ratios are the same and PDelta effects are taken into
> account in both analyses.
> However, pushover curves obtained using Drain-2dx tends to go down after
> yielding, the post-yield slope is negative for every model buildings and
> the negative slope is extremely steep for the 20-story building. While the
> pushover curves obtained using Opensees have positive post-yield slope for
> every model buildings, and the post-yield slope for every model buildings
> are almost the same, the value of post-yield slope is roughly the same as
> the product of pre-yield stiffness and strain hardening ratio.
> Has anybody perform the similar analyses using both Drain-2dx and Opensees?
> I want to know the reason of causing the significant difference of the
> results.
> Thank you very much~~

[pouyatirip2000]

hi
if u send your modeled code for me i analysis for you and help you.plz contact me !thanks

[pouyatirip2000]

If you order codes and modeling for my post, I reviewed them and your problem will go away. Also, the code written by myself, I will send you. Please contact me.

[samcivil]

Hello Mr buddhasarah,Did you get the 3-, 9- and 20-story LA buildings in SAC steel?
Now I have some problem in modeling them.Could I have your models?

[samcivil]

pouyatirip2000 wrote:
> If you order codes and modeling for my post, I reviewed them and your problem will
> go away. Also, the code written by myself, I will send you. Please contact me.
pouyatirip2000 wrote:
> If you order codes and modeling for my post, I reviewed them and your
> problem will go away. Also, the code written by myself, I will send you.
> Please contact me.


Hello Mr pouya,Did you get the 3-, 9- and 20-story LA buildings in SAC steel?
Now I have some problem in modeling them.Could I have your models?

[mzwygart]

Please send me your codes and I will take a look as well.

[strciv]

buddhasarah wrote:
> I modeled 3-, 9- and 20-story LA buildings in SAC steel project and
> performed pushover analysis using both Drain-2dx and Opensees but I found
> that the post yield behavior are completely different.
> Element type 02 is used in Drain-2dx and steel02 is used in Opensees.
> Strain hardening ratios are the same and PDelta effects are taken into
> account in both analyses.
> However, pushover curves obtained using Drain-2dx tends to go down after
> yielding, the post-yield slope is negative for every model buildings and
> the negative slope is extremely steep for the 20-story building. While the
> pushover curves obtained using Opensees have positive post-yield slope for
> every model buildings, and the post-yield slope for every model buildings
> are almost the same, the value of post-yield slope is roughly the same as
> the product of pre-yield stiffness and strain hardening ratio.
> Has anybody perform the similar analyses using both Drain-2dx and Opensees?
> I want to know the reason of causing the significant difference of the
> results.
> Thank you very much~
Dear Sarah,
If it's possible for you,please send me the SACs models OpenSees files.
I am studying the SMRF and I will evaluate these models.(My Mail: str.civ[at]gmail[d.o.t]com)
Best Regrads.

[Fahimeh]

Hello buddhasarah,

Did you solve the problem? I was wondering if you would please send me the files? If it is not OK yet we can work on them together to find the solution. I am PhD student and need the models for my research.
Thank you so much in advance.