hi
i want to use column with fiber and for the material i want to use the Ibarra model . how can i change the Ibarra model(M y-theta y) in to the stress and strain for my distributed plasticity fiber model.
??? if i can't do this ,how i can use fiber for column and concentrated plasticity for beams simultaneously.
thanks a lot.
fiber and ibbara model
Moderators: silvia, selimgunay, Moderators
Re: fiber and ibbara model
From what I know Ibarra material is developed to be used with concentrated plasticity model. Thus, I would not suggest you using it with fiber section. Steel02 would be more appropriate for this situation.
Use force-based elements for columns and zeroLenght and elastic elements for your beams.
Use force-based elements for columns and zeroLenght and elastic elements for your beams.
Re: fiber and ibbara model
hi
thanks. i appreciated your quick answer.
But if I use fiber section for my column with steel02 ,this model don’t consider strain softening in the column. And also I have a question that how many item below can consider using fiber section.
i) basic strength deterioration
ii)post capping strength deterioration
iii)unloading stiffness deterioration
iv)accelerated reloading stiffness deterioration
also is it important to consider these item in my column for IDA analyses for collapse assessment ?
(if I use force-based elements for columns and fiber section)
thanks. i appreciated your quick answer.
But if I use fiber section for my column with steel02 ,this model don’t consider strain softening in the column. And also I have a question that how many item below can consider using fiber section.
i) basic strength deterioration
ii)post capping strength deterioration
iii)unloading stiffness deterioration
iv)accelerated reloading stiffness deterioration
also is it important to consider these item in my column for IDA analyses for collapse assessment ?
(if I use force-based elements for columns and fiber section)
Re: fiber and ibbara model
Steel02 does not account for any of the items you have specified.
In collapse analysis it is important to consider those. You can try using hysteretic material with force-based elements.
In collapse analysis it is important to consider those. You can try using hysteretic material with force-based elements.
Re: fiber and ibbara model
thank u,vesna
Re: fiber and ibbara model
Hi
Please tell me a good reference about this material for steel frame.
I don’t know parameter of this model.
Thanks a lot.
Please tell me a good reference about this material for steel frame.
I don’t know parameter of this model.
Thanks a lot.
Re: fiber and ibbara model
Can anyone help me?
Re: fiber and ibbara model
Dear afakhimi
The most effective parameters are Lambda and theta coefficients that can be obtained by empirical formulas that have been given in Lignos dissertation. It must be pointed that he has used capital lambda (ᴧ) so you need convert it to small lambda (λ) by dividing to plastic rotation (Θp). The range of λ in practical usage is from 25 to 1000 (no deterioration).
Usually λa is ignored (1000) and the rest of them are equal to each other.
The most effective parameters are Lambda and theta coefficients that can be obtained by empirical formulas that have been given in Lignos dissertation. It must be pointed that he has used capital lambda (ᴧ) so you need convert it to small lambda (λ) by dividing to plastic rotation (Θp). The range of λ in practical usage is from 25 to 1000 (no deterioration).
Usually λa is ignored (1000) and the rest of them are equal to each other.
Re: fiber and ibbara model
thank u,alima2065
but my problem is considering of deterioration in the model when i use fiber in my column.
but my problem is considering of deterioration in the model when i use fiber in my column.
Re: fiber and ibbara model
Dear afakhimi
I’ve searched for using of hysteretic material in fiber model for making deterioration but there isn’t any valid report or experiment to calibrate it. So I suggest use steel02. Also take a look to section aggregator command in opensees manual and opensees wiki. May be you can make a section with different behaviors for different element forces. For example mix a fiber section and Ibarra section. Fiber is for axial forces and Ibarra section is for bending moments (I’m not sure)
I’ve searched for using of hysteretic material in fiber model for making deterioration but there isn’t any valid report or experiment to calibrate it. So I suggest use steel02. Also take a look to section aggregator command in opensees manual and opensees wiki. May be you can make a section with different behaviors for different element forces. For example mix a fiber section and Ibarra section. Fiber is for axial forces and Ibarra section is for bending moments (I’m not sure)
Re: fiber and ibbara model
thanks a lot,alima2065
In fiber section, axial force in section produce moment. P-M interaction in fiber section is considered.
Thank you for your help.
In fiber section, axial force in section produce moment. P-M interaction in fiber section is considered.
Thank you for your help.
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nparsaeifard
- Posts: 22
- Joined: Sun Jul 10, 2011 2:08 am
Re: fiber and ibbara model
Dear afakhimi
I have modeled a steel building in wich all members are modeled using fiber elements.
I also need to use hysteretic material ( to consider the deterioration)
How could you define the parameters?
Looking forward to your guidance.
Thank you
I have modeled a steel building in wich all members are modeled using fiber elements.
I also need to use hysteretic material ( to consider the deterioration)
How could you define the parameters?
Looking forward to your guidance.
Thank you