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Wrong constitutive model

Posted: Sat May 16, 2020 8:56 am
by a20145878@pucp.pe
Hi!
I am working in a model with distribuited plasticity using fiber section and I defined the constitutive model of the concrete and steel as you can see in the attached photos.
acero 1.PNG
acero 1.PNG (4.74 KiB) Viewed 634 times
acero 4.png
acero 4.png (16.33 KiB) Viewed 634 times
ca 1.PNG
ca 1.PNG (3.49 KiB) Viewed 634 times
concreto 4.png
concreto 4.png (22.44 KiB) Viewed 634 times
By the way I was using units in N and mm. However, when I run the analysis and wanted to see the results in the Fiber Color Plot, I surprised that the consitituive model of the materials in some fiber had the same shape for the steel, but not for the concrete. Hence, I attach photos about that.
concreto 3.PNG
concreto 3.PNG (5.08 KiB) Viewed 634 times
acero 3.PNG
acero 3.PNG (5.35 KiB) Viewed 634 times
. Moreover, in the Chart data I can see that for the steel the information starts almost at the beginning (0 MPa), though for the concrete starts in -10MPa approximately and there is plenty of steps with 0PMa until the end. I would really like you can help me.
Thanks in advance

Re: Wrong constitutive model

Posted: Tue May 19, 2020 4:59 pm
by STKO Team
Dear User,
may I ask you what results do yuo need to extract?
Thanks

Re: Wrong constitutive model

Posted: Wed May 20, 2020 9:57 pm
by a20145878@pucp.pe
Hi!
I wanted to extract the diagram stress and strain of some fiber, either concrete or steel, in the section of beams or columns in my model. However, I cannot understand how there is a stretch in the diagram of concrete without stress even when I defined suppostely well the consitutive model and it is correct for the steel. I cannot identify where is the mistake and I hope you can help me.
Thanks for your consideration

Re: Wrong constitutive model

Posted: Thu May 21, 2020 10:24 am
by STKO Team
Dear user,

everything looks correct, exept the fact that for small negative strains in concrete there is a first "gap" with 0 stress, which makes sense in tension (0 tensile strength) but not in compression.

Please attach your SCD file here and we will have a look

Re: Wrong constitutive model

Posted: Thu May 21, 2020 7:35 pm
by a20145878@pucp.pe
Hi!
As you said, is it possible that there is a stretch in the diagram that could be in tension even when I defined the behaviour just in compression with the command concrete01?. Moreover, Can I send you the file by e-mail?
Thanks