Peak-Orinted

[Alia]

Hi Silvia
Are deteriorating model for Peak-Oriented hysteretic systems implemented in Opensees? If not, what is equivalent model in Opensees?

Sincerely yours.

[silvia]

i don't know what those are.

[Alia]

Hi Silvia,

We mean the deteriorating model based on hysteretic energy dissipation that has been presented by Ibarra & Krawinkler in John A. Blume Earthquake Engineering Research Center Report No. 152. We want to use these basic cyclic deteriorating rules for peak-oriented hysteretic models. How can we do this?

Sincerely yours.
Alia.

[silvia]

i don't know it.
see if any opensees material can do the behavior you want.
otherwise, you can develop one that does.

[zvidrih]

Hi,

I think what You nead is Clough material. Unfortunately it's not included in the documentation (manual), so you'll have to check the parameters.

As I recal, the function call looks sth. like this:

Code: Select all

uniaxialMaterial Clough $tag $Ke $My $My- $αc  $resFac $αpc $θcap+ $θcap- $λc $λpc $c

The meaning of some of the parameters can be seen from the following picture.



You can find out more about parameters in:

http://peer.berkeley.edu/publications/p ... erlein.pdf

You can also check the class file for reference

http://opensees.berkeley.edu/OpenSees/a ... lough.html

[silvia]

the hysteretic material, well documented and working well, can do that envelope, but will not stop at zero on the way down.

[zvidrih]

Yes, one can use hysteretic material, but I think, what they are talking about in the report, that was mentioned earlier is strength and stiffness degradation, like the one shown in the pic.



Note, that black line is the monotonic envelope, which is used as input data.

[silvia]

yes, hysteretic can handle it.
just try it

[Jean Domínguez]

it´s the clough material included in the OpenSees download package or we must load it from an external code or something....? i can´t see any reference about it in the documentation.

[Jean Domínguez]

I can´t find the multi-cycle graphic for Hysteretic Material, there´s only a backbone curve, howerver there´s a well documented stiffness and strength degradation behavior for the "limit state material" in the sub-cap "Pinching4 uniaxial material model" page 90

[silvia]

did you go to the on-line manual.
the page right after it, or the one after that.

[Trirat_to]

Hi, zvidrih

Do you know which element did they use for the hysteretic material in the report?

Thank you
Trirat

[zvidrih]

Hi, sorry for late response,

I am quite sure, that "Clough" material, implemented in OpenSees, is actually the Ibarra model

Copy pasted from PEER report:
"Altoontash (2004) implemented this model into OpenSees (2006) as a material model that is accessed through the “Clough” material model command. Note that this name “Clough” is a misnomer, as the actual model is based on the work by Ibarra and Krawinkler (Ibarra 2003; Ibarra et al. 2005)."

PEER 2007/12 - An Assessment to Benchmark the Seismic Performance of a Code-Conforming Reinforced Concrete Moment-Frame Building
Curt B. Haselton, Christine A. Goulet, Judith Mitrani-Reiser, James L. Beck, Gregory G. Deierlein, Keith A. Porter, Jonathan P. Stewart, Ertugrul Taciroglu.

See my post above for additional information on Clough material.

Hope it helps

[Jean Domínguez]

I´m reading about this hysteretic model and found this:

- Maybe the "clough" name isn´t a misnomer, Ibarra et al. says: "This model keeps the basic hysteretic rules proposed by Clough and Johnston and later modified by Mahin and Bertero, but the backbone curve is modified to include strength capping and residual strength..." (Earthquake Engineering and Structural Dynamics Vol 34 N 12 2005).

- Haselton and Deierlein (2007 report 156 John Blume earthquake engineering center) write this warning: "We also set the unloading stiffness deterioration mode to have zero deterioration" and explains in the footnote " ...because there is currently an error in the Opensees implementation of the model: this error causes incorrect cyclic responses when the unloading stiffness deterioration mode is employed.
They´re talking about one must use always $c=0 , i think.