Material analysis

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Chunlong LU
Posts: 2
Joined: Tue Mar 01, 2022 11:26 am

Material analysis

Post by Chunlong LU » Wed Mar 02, 2022 12:35 am

Dear STKO team,
Hello, I am a beginner of STKO software. During this period, I built a shear wall model, but there were some mistakes during the operation analysis, FAP material could not find the direction of principal stress, and there was no post-processing result. I don't know how to debug such mistakes, so I want to see how others solve this problem.

Any suggestions on what may cause this is very much appreciated. The model is added.
Attachments
shearwall.zip
(153.13 KiB) Downloaded 142 times
analyse.png
analyse.png (59.96 KiB) Viewed 1763 times

STKO Team
Posts: 3066
Joined: Tue Oct 29, 2019 8:45 am

Re: Material analysis

Post by STKO Team » Wed Mar 02, 2022 10:14 am

You need to revise your model.
There are a lot of errors:

1) Pay attantion to material parameters that should be negative (look at the bottom part of the editor, there is a description of the parameter). Also, use the material tester to make sure your parameters are correct.

2) The Fiber section needs a GJ > 0

3) The ELastic section has an unrealistic G modulus

4) The Fiber section has some zeros in diameters, leading to division by zeros...

Please, check these values and upload an updated model

Chunlong LU
Posts: 2
Joined: Tue Mar 01, 2022 11:26 am

Re: Material analysis

Post by Chunlong LU » Sat Mar 05, 2022 4:34 am

Dear STKO team,
First of all, thank you very much for your advice.According to your suggestion, I revised the material related to FAPrestressedConcretePlaneStress. However TendonL01 material cannot be tested, and ConcreteZ01 material test type varies greatly in Stress value, and there were still something wrongs with the material of FAPrestressedConcretePlaneStress during the analysis.
In addition, I downloaded a correct layered shell shear wall model from the forum, and the wall material was changed to FAFourSteelRCPlaneStress material, but Errors related to FAReinforceConcretePlaneStress will occur after the layered shell model can only run partially. I don't know why FAFourSteelRCPlaneStress material is used. but the model analysis showed error related to FAReinforceConcretePlaneStress material.
Any suggestions on what may cause this is very much appreciated. The Modified model and layered shell model wear added.
Attachments
shearwall and layerwall.zip
(334.34 KiB) Downloaded 153 times

STKO Team
Posts: 3066
Joined: Tue Oct 29, 2019 8:45 am

Re: Material analysis

Post by STKO Team » Mon Mar 07, 2022 9:07 am

A little suggestion:
Don't use those materials, even in the OpenSees documentation they say that lots of them do not work correctly.

In my opinion, you will never make it work, simply because those materials look non properly coded. Try to have a look at our webinar on shear walls to see some alternatives (webinar #2)


I just had a look at the ConcreteZ01, and if you test it in a cyclic test, you will see how inconsistent it is:
what.png
what.png (78.63 KiB) Viewed 1720 times

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