Support for 2D PML elements

[jfhuang]

Hello STKO team,

I was trying to record results for the PML elements implemented in OpenSees (https://github.com/OpenSees/OpenSees/pull/503). The mpco recorder seems to work for the 3D PML elements (8-node element) well as shown in the attached image "PML3D.png".

However, it does not work for the 2D PML elements (4-node element), as shown in the attached images "PML_2D (include PML elements).png" (obtained with the newest version compiled by Prof Tarque on Oct 14, 2021, https://drive.google.com/file/d/1ETGQ3Y ... 5Mk7C/view, as seen the analysis stopped at the first step) and "PML_2D (include PML elements, Linux version).png" (compiled on linux, which showed a Segmentation fault was encountered). On the other hand, if I only record regions composed of "normal" elements (2D plane strain elements) the analysis could proceed but of course, no results for the PML elements were recorded (see "PML_2D (exclude PML elements).png").

Based on the above tests, additional efforts may be needed to support the 2D PML elements in STKO and it would be great if we can have it! Thanks in advance!

Regards,
Junfei

[STKO Team]

Dear user,
Thank you for spotting this issue.
Probably it is an incompatibility on how the PML2D creates results. If you could send me a Tcl file to test it, I will debug it to speed up the identification of the bug.
We will also add support for the PML in the stko pre processor

[StavrosP]

Hello,

is there an update about when the PML elements will be added to the STKO pre-processor?

Thanks,
Stavros

[STKO Team]

Not yet. I don't think we will add it soon, because it seems like the 3D PML is not working properly.
Anyway, on the 15th of December we will do a webinar on a new tool for soil modelling (DRM: Domain Reduction Method)

[jfhuang]

Hi, sorry for the delayed response, I was much bogged down by other appointments. Attached please find an minimum example of 2D PML elements that leads to Segmentation fault during runtime. The analysis can proceed by commenting out the "recorder mpco ..." line, indicating the Segmentation error comes from the MPCO recorder. Hope this can get fixed soon. Thanks!

PS: This error happens when using the latest OpenSees source code (as of Nov 21, 2023).

[jfhuang]

Hi, just want to have a quick follow-up on this?

[STKO Team]

I run your example and it seems the segmentation fault happens also without the mpco recorder if I use the latest OpenSees.
With a previous version, it happens only if I have the mpco recorder.

I think the source of the segmentation fault is still in the PML element. Unfortunately now we don't have time to look into it.

[jfhuang]

Oh got it, thank you for the response.

[STKO Team]

You're welcome