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Error in Analysis
Posted: Tue Feb 23, 2021 1:55 pm
by Zeeshanbhat
Dear Team,
I tried to model the RC Frame building according to your tutorial, but I am getting an unexpected error in the analysis as shown in the attached file. Could you please help me in identifying this error.
With Regards,
Zeeshan Bhat
Re: Error in Analysis
Posted: Thu Feb 25, 2021 10:54 am
by AcetoDivino
Hi Zeeshanbhat,
You did not assign the sections at 4 columns of the ground floor, also the master node constraint is missing in the constraint pattern.
![2021-02-25 11_52_01-STKO (Version 2.0.0) - PreProcessor [model].png](./download/file.php?id=940)
- 2021-02-25 11_52_01-STKO (Version 2.0.0) - PreProcessor [model].png (182.36 KiB) Viewed 4174 times

- 2021-02-25 11_52_20-AnalysisStep Editor.png (16.52 KiB) Viewed 4174 times
Now it works.
Luca
Re: Error in Analysis
Posted: Thu Feb 25, 2021 2:05 pm
by Zeeshanbhat
Thank you Luca
Re: Error in Analysis
Posted: Thu Feb 25, 2021 2:34 pm
by AcetoDivino
Hi Zeeshanbhat,
The model is giving you problems because you didn't put any masses.
![2021-02-25 15_30_58-STKO (Version 2.0.0) - PreProcessor [TRY NEW ONE_].png](./download/file.php?id=948)
- 2021-02-25 15_30_58-STKO (Version 2.0.0) - PreProcessor [TRY NEW ONE_].png (18.88 KiB) Viewed 4152 times
If you put them the analysis will work fine.
![2021-02-25 15_30_58-STKO (Version 2.0.0) - PreProcessor [TRY NEW ONE_]_2.png](./download/file.php?id=949)
- 2021-02-25 15_30_58-STKO (Version 2.0.0) - PreProcessor [TRY NEW ONE_]_2.png (66.04 KiB) Viewed 4152 times
Please check out the training section of the site
http://www.asdeasoft.net/stko?stko-training where there is a lot of useful content to help resolve these issues.
In this Webinar
https://www.youtube.com/watch?v=vUXKVm5 ... Technology P.hD Petracca explains how to do response spectra analysis
Luca
Re: Error in Analysis
Posted: Mon Mar 01, 2021 11:57 am
by Zeeshanbhat
Dear Luca,
Thank you so much.
Could you please send this file here.
Regards,
Zeeshan Bhat
Re: Error in Analysis
Posted: Tue Mar 02, 2021 1:10 pm
by Zeeshanbhat
Dear Luca,
Thank you. I applied the mass and did eigenvalue analysis also. However, it is not converging in pushover analysis after some increments. Could you please have a look at the fibre section of beams, whether I have developed them correctly or not?. Actually I am getting non-convergence issue in beams only. Also could you please give some suggestions, on how to overcome this convergence issue?
Regards,
Zeeshan Bhat
Re: Error in Analysis
Posted: Tue Mar 02, 2021 4:37 pm
by marafini.f
Dear Zeeshan,
Thank you for your question.
Your material parameters for Concrete02 are completely wrong.
The lamba is too small and the Et is too high and the model fails too quickly in tension and produces instability in the forceBeamColumnElement. This you could have spotted by checking your material with the material tester

- image.png (33.99 KiB) Viewed 4113 times
or by checking your results, identifying at which level of stress the beam were failing, which corresponded to the tensile strength you assigned.
I attach a model with better parameters you can continue working on.
As I already suggested you before, If I were you, I would try to apply what you learn in the webinars on your work applications, something you can control better and you have more sources to consult. Accurately set up material properties and analysis setup, using all the tools STKO provides to check your model thoroughly before posting a question. I am sure you will encounter new and stimulating problems we can discuss together.
Francesca
Re: Error in Analysis
Posted: Wed Mar 03, 2021 4:29 am
by Zeeshanbhat
Dear Francesa,
Thank you so much.
Regards,
Zeeshan Bhat
Re: Error in Analysis
Posted: Wed Mar 03, 2021 8:53 am
by marafini.f
Dear Zeesha Bhat,
Glad I could help, thank you for your question.
Enjoy your modeling.
Francesca