Surface color plot seems cannot be displayed correctly under specific circumstances

[ZhangBin]

Dear STKO team,

I am trying to model pile-soil interaction and observe the soil strain distribution, but when I open the material.strain plot, some region seems cannot be displayed properly. Other plots, like the displacement plot, can be displayed correctly.
I use the OpenSeesMP solver to do the analysis, the region that cannot be shown seems related to the mesh partition, as shown in the following picture.
I wonder if anyone can tell me what is the reason for this situation and how can I solve it.

Thank you for your attention.
Zhang Bin

[marafini.f]

Dear Zhang Bin,

The error you are experiencing can occur when you try to open your database while the analysis is still running. Also, you can have this problem if you run your analysis twice but changed the number of processors and did not erase the previously created databases.

There are also other cases, but first please try to run your analysis in a new folder and open the database only when OpenSees has finished.
Let us know how it goes.

Francesca

[ZhangBin]

Dear Francesca,

Thanks for your quick reply, I will run my analysis as you said.

regards,
Zhang Bin

[marafini.f]

You are welcome!

[ZhangBin]

Dear STKO team,

As you suggested, I rerun my model in a new folder. After closing OpenSees, I open the database that located the new folder. But the situation still exists. I found the region that cannot be displayed has "brickUP" element property, in the same partition, the region that has "SSPbrick" element property is able to show in the plot. I wonder if it is caused by the existence of different element types in the same partition. If so, how can I solve it?

regards,
Zhang Bin

[marafini.f]

Dear Zhang Bin,

if you did not open the file until the analysis was completed and let STKO create all the partitioned database from scratch the problem could be that the analysis did not reach convergence in that specific partition and therefore you can't see the results.

Would you share your model with us so we can have a look?

Best,
Francesca

[ZhangBin]

Dear Francesca,

Here is my model, thanks for your support!

Best,
Zhang Bin

[STKO Team]

Dear Zhang Bin,

we identified the issue, and it belongs to the PressureDependMultiYield that does not follow the standard OpenSees rules for writing the results.
This is not a problem typically, but when you mix this material with others (in your case the ElasticIsotropic) in a partitioned mesh, it can confuse the STKO post processor.

We will fix this issue either in OpenSees, or we will implement a workaround in the STKO post processor able to fix this issue in post processing.

In the meantime, you can solve it creating 2 recorders: 1 for SOIL and 1 for STRUCTURE, where SOIL and STRUCTURE are 2 regions.
In this way you keep the two materials into separate databases.
Here is how I did it:

pilegroup_Zhangbin0728.zip

(575.72 KiB) Downloaded 222 times

Then in the post processor you can open both of them and create 2 plots into the same plot group. Note that this issue only happens with "strain" and "material.strain".

[ZhangBin]

Thank you!

[STKO Team]

You are welcome!