Buckling

[reza2333]

Dear Friends,
Can we use Reinforcing Steel Material in modeling buckling for braces? What changes should be done on specific parameters?

[pejman_opensees]

Hi
Why do you wanna do such a thing? What is wrong with steel02 material?
you may get the result in case of monotonic loading but you will have much trouble in cyclic loading. the best way to make sure that your braces work properly is using steel02 material.

[reza2333]

How can I model post buckling behavior with Steel02 material?
Do you have any example of braces modeled with this material?
Tnx

[pejman_opensees]

I actually do. search in useful script room for the post that I have sent. one of them is exactly what you are looking for.

[Ben-Peng]

Hi, pejman! I read your script about the Buckling in Useful Scripts. But I want to know that whether your script accounted for the local buckling? Thanks!

[pejman_opensees]

The script I wrote is somehow a reformed version of Dr.Patxi uriz codes. Actually I was working on the subject while he had already finished his work and I did not know that. By the way, to answer your question I can say that most uniaxial elements normally are not able to account for local buckling since they are uniaxial! unless a suitable damage model is embedded so that local buckling due to low cyclic fatigue or local buckling due to low D/t ratio can be modeled. force beam column element does not support such a characteristic but as far as I know fatige material written by Dr.Uriz has capability to consider low cyclic fatigue and degraded behavior. But currently I am working on this topic as my primary research to add a uniaxial element in Opensees which can model local buckling due to low D/t ratio.

[Ben-Peng]

thanks for your reply, Pejman! I am glad to hear that you focus on this area.