How can visualize horizontal , vertical stress in soil domain

[BuuNguyen]

Hello STKO team,

my model is in 3D. I used SSP-BrickUP element for soil domain.
For setting recorder, I ticked "material stress", "material strain" to see vertical and horizontal pressure in soil.
But they are not present in my post-processor window, or if they are present. I can not see the distribution of vertical and horizontal stress in soil.

How can I visualize horizontal , vertical stress in soil domain in post-processor?

Thank you for your support,
Buu

[STKO Team]

That's because the SSP brick elements do not support the "material" keyword before the "stress" keyword (they have only 1 integration point)

So you can simply use the custom results an input "stress" only:

ssp.png (42.99 KiB) Viewed 758 times

[yuweihwang]

Hello STKO,

By using custom "stress", we can see the results in the contour plots. However, it still cannot show results if we looked at gauss point plots. Should we add any additional keywords?

Thanks in advance,
Yu-Wei

[marafini.f]

Not sure if this helps, but in the SSP-BrickUP element it says:
"Valid queries to the SSPbrickUP element when creating an ElementalRecorder object correspond to those for the nDMaterial object assigned to the element (e.g., 'stress', 'strain'). Material response is recorded at the single integration point located in the center of the element."

Is this integration point not even visible in the Gauss Plot?
Francesca

[BuuNguyen]

Hello STKO,

By using custom "stress", we can see the results in the contour plots. However, it still cannot show results if we looked at gauss point plots. Should we add any additional keywords?

Thanks in advance,
Yu-Wei

Hi STKO, I have the same question, the stress result can be seen in the contour, but it can not be extracted from "Extract data" function. How can I extract the data?
Thank you.
Buu

[STKO Team]

If you can see the stress in the surface plot, you should be able to see it in the gauss plot as well.
From the gauss plot, you can extract the data.

If it doesn't work for you, please share more information to understand what is the issue

[BuuNguyen]

Hi STKO,
As you can see in Figure 1 which is surface color map, I can show volume stress (6 components, all values is 0) and volume stress (7 components). what is the difference between them? (as your suggestion, I added "stress" in custom element results of recorder to get stress of SSPBrickup element).
In figure 2 which is gauss point plot, I cannot see any gauss point in soil domain, and the volume stress (7 components) disappear, it has only volume stress (6 components).

you can scroll up to see Francesca's question: "Is this integration point not even visible in the Gauss Plot?"

Thank for your time
Buu

[STKO Team]

You are right, we just realized that the combination of SSPBrickUP and a PDMY (PDMY02) material is missing some information when recording output from OpenSees.

Due to this, STKO does not understand how to make the Gauss Plot.
We will fix this in the OpenSees source code as soon as possible.

In the meantime, you can use this Python API script to extract a stress-strain chart for each selected element in a surface plot:
Try to use it, if you don't understand the code or you don't know how to use it, let us know.
Tomorrow we will have a webinar, if you have questions about this, we can show it after the webinar:

[BuuNguyen]

actually, I got this errors when running the code as shown in Figure 1
what is the problem?

There are 2 stress in the plot: Volume stress (6 components) and Volume stress (7 components) as in Figure 2.
I am trying to extract stresses from Volume stress (7 components), I dont know the difference between 2 types of volume stress but in Volume stress (6 components), all values are 0.
Buu

[BuuNguyen]

Hi STKO team,
After reading carefully and understand your code,
I modified it to get stress component only and plot it vs time. However, I always get "Not responding" in STKO when running the code. what is the problem in this case?
Please have a look at my modified code.
Thank you