Rebar constitutive model including softening segments

[haishui]

Hi,everyone.

I’ve been working on simulating uniaxial tensile tests of rebar using STKO, and I’m currently using the reinforcing steel material model to capture its tensile behavior. However, I’ve noticed that the softening part of this model isn’t pronounced enough, and it doesn’t really represent the fracture process of the rebar under tension very well.

I was wondering if there are some material models in STKO that can more effectively simulate the tensile behavior and fracture process of rebar? I’m particularly interested in models that show a clearer softening response.

Thanks so much for your help!

[STKO Team]

Look at the new ASDSteel1D we just developed.
We have a webinar (the last one), and the documentation is here:
https://opensees.github.io/OpenSeesDocu ... eel1D.html

[haishui]

Look at the new ASDSteel1D we just developed.
We have a webinar (the last one), and the documentation is here:
https://opensees.github.io/OpenSeesDocu ... eel1D.html

Thank you for replying! When I test this constitutive model, a problem appeared in the material testing interface.

屏幕截图 2026-01-13 194331.png (42.25 KiB) Viewed 219 times

Accompanied by this error message：
Traceback (most recent call last):
File "E:\Program Files/STKO\external_solvers\opensees\physical_properties\utils\tester\Tester1D.py", line 915, in onTestClicked
self.tester.run()
File "E:\Program Files/STKO\external_solvers\opensees\physical_properties\utils\tester\Tester1D.py", line 208, in run
os.remove(temp_output_file)
FileNotFoundError: [WinError 2]: 'C:/Users/haishui leng/AppData/Local/ASDEA Software Technology/STKO/Tester1D/output.txt'
Looking forward to your reply.

[STKO Team]

You should read the full OpenSees error in the STKO's terminal.
However, I'm pretty sure you have an old version of OpenSees that does not have this new material model