Reg. 3D nDMaterial suitable for prestress concrete

[tusharkantimandal]

hi all,
Can anyone plz. suggest me any three dimensional nDMaterial suitable for NonLinear analysis of Prestress Concrete structure?
waiting for your suggestions....................

[vesna]

as of now we do not have such material.

[tusharkantimandal]

vesna wrote:
> as of now we do not have such material.
Hi Vensa,
Can you plz. suggest any alternatives?

[vesna]

As of now we do not have reliable material for concrete that would work in 3d.

[tusharkantimandal]

vesna wrote:
> As of now we do not have reliable material for concrete that would work in
> 3d.
Hi Vensa,
Thank you very much for your regular reply...
one more query...
can we define a new 3-d material?.. how tough that work?.. means how long it may take for a m-tech student?.. is it feasible/possible or not?
waiting for your suggestions.........

thanking you,
Tushar
IIT Bombay

[vesna]

OpenSees is open source so it is possible to add new classes to OpenSees. If you have some programing skills and enthusiasm about doing it you can do it. Here are resources that can help you start:
http://opensees.berkeley.edu/wiki/index ... r_own_Code
http://opensees.berkeley.edu/wiki/index ... ew_Element
http://opensees.berkeley.edu/OpenSees/d ... /index.php

If you develop reliable material the OpenSees community would be happy to have access to it.

[leopoldo.tesser]

I can suggest you to use the Drucker Prager material model.
You can have fair estimations in case of monotonic analysis, whereas it is not suitable for cyclic analysis.
Here you have the link to opensees wiki:
http://opensees.berkeley.edu/wiki/index ... ker_Prager
With some colleagues, I have implemented a 3D concrete plastic-damage model and hopefully I will be able to add it to the opensees repository soon.

[tusharkantimandal]

leopoldo.tesser wrote:
> I can suggest you to use the Drucker Prager material model.
> You can have fair estimations in case of monotonic analysis, whereas it is
> not suitable for cyclic analysis.
> Here you have the link to opensees wiki:
> http://opensees.berkeley.edu/wiki/index ... ker_Prager
> With some colleagues, I have implemented a 3D concrete plastic-damage model
> and hopefully I will be able to add it to the opensees repository soon.
I want to do NonLinear time-history analysis.. then I think drucker-prager will not be suitable. Waiting for your new 3D concrete plastic-damage model.. Hope that will help me.. thank you so much....

[gerber]

Hi !
I want to use Drucker Prager (D-P) material model for concrete .
I am not sure how to use it .... has anyone any idea ?
I can`t find the connection between D-P parameters and concrete`s fc,E,ecu...

Thank you...

[leopoldo.tesser]

The DruckerPrager material model implemented in opensees is explained in the openseeswiki webpage:
http://opensees.berkeley.edu/wiki/index ... ker_Prager
The elastic paramters are: k,G
bulk modulus: k=E/(3*(1-2*ni))
Shear modulus: G=E/(2*(1+ni))
The yield surface parameters are: sigmaY,rho
sigmaY=2*|fcc|*fct/(|fcc|+fct)
rho=sqrt(2/3)*(|fcc|-fct)/(|fcc|+fct)
where
E = Young's modulus
ni = Poisson's modulus
fcc = elastic threshold in uniaxial compression
fct = elastic threshold in uniaxial tension
The other parameters control the plastic flow and are well detailed in the cited link.

Leopooldo Tesser

[gerber]

I have found a litle different equations in wikipedia : [ http://en.wikipedia.org/wiki/Drucker%E2 ... _criterion ]
Unfortunately , I think I could not use Drucker Prager for my 2D problem of inframed shear wall with quad or shell elements.
Probably I should use an other finite element analysis software
Thank you very much for your Information.