Simplified bilinear hysteresis

[mattfox]

Dear Seismosoft,

Two questions on the Takeda hysteresis rule as described in the SeismoStruct (V6) help manual.

1) The diagram shows the first reloading branch of the loop going to some arbitrary point. What defines this point and why does it not go to the yield point instead?

2) Where does the beta1 factor come from? It is not included in any of the references e.g Otani 1981.

Hope you can help.

MF

[seismosoft]

Dear MF,

Parameter Beta1 is defined as the 'Inner loop stiffness degradation factor'.

For what concerns the reloading point you mention, we will send you via email the full algorithm, so that you may follow the operations yourself.

Kind regards,

Seismosoft Support

[amir_nayebe65@yahoo.com]

Dear Seismosoft,
1)questions on the Takeda hysteresis rule as described in the SeismoStruct: can i use this hysteresis in steel modeles or its just for R/f concrete models?
2)i'm using steel model and i need a hystersis model that it have a degradation in strength.could you plz help me to find the best hystersis model?

[Stelios_Antoniou]

The takeda curve was initially developed for the hystereitc curve of R/C elements. It is mainly up to you and your supervisor to decide if the curve is suitable for the structural configuration of your steel model.

Stelios Antoniou
SeismoSoft Developer

[amir_nayebe65@yahoo.com]

dear Stelios_Antoniou
i read help of takeda hystersis model but the parameteres Description is not enouagh to decide about how to use them and how should i change the parameteres.i can not access the paper which describe the simplification of takeda hystersis model(Otani S. [1981] "Hysteresis Models of Reinforced Concrete for earthquake Response Analysis," Journal of Faculty of Engineering, University of Tokyo).i live in iran and i have some limitation to access some papers.how can i know about the parameteres?how can i read the algorithm?
Hope you can help me
A.N

[Stelios_Antoniou]

Hi Amir,
I would suggest that you carry out a Google search (both the web and Google Scholar) for the Otani model, there should be plenty of information and resources on it.
Regarding the code, any indivudual with basic understanding of progtramming, should be able to read it and understand it.

Stelios Antoniou
SeismOSoft Developer