P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

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

Moderators: silvia, selimgunay, Moderators

Post Reply
HajMaf
Posts: 4
Joined: Mon Jan 07, 2019 7:33 pm
Location: The University of Melbourne

P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

Post by HajMaf » Thu Oct 24, 2019 4:20 pm

I have Modelled a Modular building in Opensees. This Includes Boxes( Modules-made of shell elements) connected with two node link elements to form a building as shown below.

We also developed an experimental model of the same and noticed the results for the top displacement.
I could notice that there is a shift (shifting upward) of the baseline in the experimental results which i believe is due to the P-delta effects while the experimental results, top displacement base line was on Y=0 line, i.e X axis. Also i can see that my Opensees Model has no way of getting P-delta effects activated because Neither two node link element nor the shell elements used to model the boxes have coordinate transformation feature.

May i please get your idea on this? how can i let my Opensees model take in to account the P-delta effects? is there any other way to account for that? Or is it not the P-delta effects that's causing the shift of the base line?

I tried adding a leaner column, but it wasn't successful. i followed the exact procedure mentioned for that on Opensees website. But the eigenvalues were imaginary.

selimgunay
Posts: 634
Joined: Mon Sep 09, 2013 8:50 pm
Location: University of California, Berkeley

Re: P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

Post by selimgunay » Sat Nov 09, 2019 11:49 am

For this case, leaning column is the only option to consider p-delta effects. Imaginary eigenvalue can be because the leaning column itself is unstable as it has a hinge at the bottom and connected to only axial trusses. Did you assign masses to the leaning column ?

HajMaf
Posts: 4
Joined: Mon Jan 07, 2019 7:33 pm
Location: The University of Melbourne

Re: P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

Post by HajMaf » Sun Nov 10, 2019 1:51 pm

Hi Yes, i assigned masses to the leaning column. But still i keep getting imaginary Eigenvalues. IS the leaning column method valid for 3D models as well? mine is a 3d Model, but i assigned a leaning column to the first frame of the building only.

"Imaginary eigenvalue can be because the leaning column itself is unstable as it has a hinge at the bottom and connected to only axial trusses" if this is the case, what do you recommend to solve this issue?


Doostihaa
Posts: 6
Joined: Tue Nov 12, 2019 12:34 pm
Location: IRAN
Contact:

Re: P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

Post by Doostihaa » Sat Nov 16, 2019 5:15 am

S the leaning column method valid for 3D models as well? mine is a 3d Model, but i assigned a leaning column to the first frame of the building only.
https://www.doostihaa.com/1398/08/25/دا ... و-نیم.html
https://www.doostihaa.com/1399/03/25/دا ... -برقص.html
https://www.doostihaa.com/1398/08/25/دا ... -پدری.html
the leaning column itself is unstable as it has a hinge at the bottom and connected to only axial trusses" if this is the case.
Last edited by Doostihaa on Sun Jun 14, 2020 3:43 am, edited 1 time in total.


Doostihaa
Posts: 6
Joined: Tue Nov 12, 2019 12:34 pm
Location: IRAN
Contact:

Re: P-Delta Effects for Models With Elements which doesn't include Geometric Transformation

Post by Doostihaa » Sun Nov 24, 2019 5:12 pm

S the leaning column method valid for 3D models as well? mine is a 3d Model, but i assigned a leaning column to the first frame of the building only.
https://www.doostihaa.com/1398/09/04/دا ... مانکن.html
https://www.doostihaa.com/1398/09/04/دا ... ن-است.html
https://www.doostihaa.com/1398/09/04/دا ... -تعصب.html
https://www.doostihaa.com/1398/09/05/دا ... نی-ها.html
https://www.doostihaa.com/1398/09/07/دا ... کرگدن.html
https://www.doostihaa.com/1398/09/09/دا ... فید-۳.html
https://www.doostihaa.com/1398/09/11/دا ... مانکن.html
https://www.doostihaa.com/1398/09/18/دا ... مانکن.html
https://www.doostihaa.com/1398/09/25/دا ... -مانکن.htm
https://www.doostihaa.com/1398/10/02/دا ... مانکن.html
https://www.doostihaa.com/1398/10/09/دا ... مانکن.html
https://www.doostihaa.com/1397/09/20/دا ... دقیقه.html
https://www.doostihaa.com/1398/09/14/دا ... -لارج.html
https://www.doostihaa.com/1398/09/14/دا ... شیرین.html
https://www.doostihaa.com/1398/09/14/دا ... کرگدن.html
https://www.doostihaa.com/1398/09/14/دا ... ال-دل.html
https://www.doostihaa.com/1398/09/17/دا ... مل-شد.html
https://www.doostihaa.com/1398/09/20/دا ... ال-دل.html
https://www.doostihaa.com/1398/09/27/دا ... ال-دل.html
https://www.doostihaa.com/1398/10/04/دا ... ال-دل.html
https://www.doostihaa.com/1398/10/11/دا ... ال-دل.html
https://www.doostihaa.com/1398/09/21/دا ... کرگدن.html
https://www.doostihaa.com/1398/09/28/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/05/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/12/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/02/دا ... -روسی.html
https://www.doostihaa.com/1398/10/04/دا ... -و-من.html
https://www.doostihaa.com/1398/10/04/قس ... ومینو.html
https://www.doostihaa.com/category/mult ... ino-series
https://www.doostihaa.com/1398/10/05/دا ... م-رقص.html
https://www.doostihaa.com/1398/10/09/دا ... برلین.html
https://www.doostihaa.com/1398/10/10/دا ... م-قسم.html
https://www.doostihaa.com/1398/10/19/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/15/دا ... ر-مار.html
https://www.doostihaa.com/1398/10/16/قس ... مانکن.html
https://www.doostihaa.com/1398/10/23/قس ... مانکن.html
https://www.doostihaa.com/1398/10/18/دا ... ال-دل.html
https://www.doostihaa.com/1398/10/19/دا ... ا-تختی.htm
https://www.doostihaa.com/1398/10/25/دا ... ال-دل.html
https://www.doostihaa.com/1398/10/23/دا ... سرکوب.html
https://www.doostihaa.com/1398/10/23/دا ... -نبات.html
https://www.doostihaa.com/1398/10/26/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/26/قس ... ب-زده.html
https://www.doostihaa.com/category/mult ... ess-series
https://www.doostihaa.com/1398/11/02/دا ... ال-دل.html
https://www.doostihaa.com/1398/11/02/دا ... کرگدن.html
https://www.doostihaa.com/1398/10/30/قس ... مانکن.html
https://www.doostihaa.com/1398/11/07/قس ... مانکن.html
https://www.doostihaa.com/1398/11/09/دا ... ونگاه.html
https://www.doostihaa.com/1398/11/10/دا ... کرگدن.html
https://www.doostihaa.com/1398/11/10/دا ... ال-دل.html
https://www.doostihaa.com/1398/11/11/دا ... -اصلی.html
https://www.doostihaa.com/1398/11/11/قس ... ب-زده.html
https://www.doostihaa.com/1398/11/16/دا ... -مطرب.html
https://www.doostihaa.com/1398/11/14/دا ... -چاقی.html
https://www.doostihaa.com/1398/11/21/دا ... پیلوت.html
https://www.doostihaa.com/category/mult ... es/moochin
https://www.doostihaa.com/1398/11/13/قس ... موچین.html
https://www.doostihaa.com/category/mult ... s/hamgonah
https://www.doostihaa.com/1398/11/22/قس ... -گناه.html
https://www.doostihaa.com/1398/11/14/قس ... مانکن.html
https://www.doostihaa.com/1398/11/21/قس ... مانکن.html
https://www.doostihaa.com/1398/11/28/قس ... مانکن.html
https://www.doostihaa.com/1398/11/18/قس ... ب-زده.html
https://www.doostihaa.com/1398/11/16/دا ... ال-دل.html
https://www.doostihaa.com/1398/12/14/دا ... -1400.html
https://www.doostihaa.com/1398/11/20/دا ... ه-دار.html
https://www.doostihaa.com/1398/11/24/دا ... -سایه.html
https://www.doostihaa.com/1398/11/24/دا ... م-آکو.html
https://www.doostihaa.com/1398/11/26/دا ... -آنها.html
https://www.doostihaa.com/1398/12/01/دا ... اه-کش.html
https://www.doostihaa.com/1398/12/07/دا ... گمشده.html
https://www.doostihaa.com/1398/12/09/دا ... -دخمه.html
https://www.doostihaa.com/1398/12/09/دا ... شیطان.html
https://www.doostihaa.com/1399/01/19/دا ... -خروج.html
https://www.doostihaa.com/1399/01/05/دا ... د-خون.html
https://www.doostihaa.com/1399/01/17/شک ... تخوان.html
https://www.doostihaa.com/1399/01/05/دا ... زارتو.html
https://www.doostihaa.com/1399/01/31/دا ... -بسته.html
https://www.doostihaa.com/1399/01/31/دا ... معکوس.html
https://www.doostihaa.com/1399/01/19/دا ... -خروج.html
https://www.doostihaa.com/1399/02/04/دا ... ی-بود.html
https://www.doostihaa.com/1399/02/08/دا ... ی-نهم.html
https://www.doostihaa.com/1399/02/08/دا ... م-طلا.html
https://www.doostihaa.com/1399/02/11/قس ... ازاده.html
https://www.doostihaa.com/category/mult ... agha-zadeh

Post Reply