Smooth and multi-linear curves

[isuste]

Hello,

I have started trying out the newly added hysteresis curves in version 5.2.1., namely the smooth and multi-linear curve.
So far I have tried just simple SDOF tests with cyclic displacement loading trying to simulate the behaviour of a specific connection. Unfortunately I am not getting any response - the displacement is being applied and the system is converging but there is no force being recorded. I am using the default parameter values for both of the curves and the FE model setup works well with other types of curves.

Best regards,
Iztok

[seismosoft]

Hi Iztok,

You are right. Something does not seem to be working with these curves. We will look into this matter and then let you know.

Thanks for reporting this problem to us.

Seismosoft Support

[seismosoft]

Dear Iztok,

We are still looking into this matter.

In the meantime, could you perhaps try using a (much) lower displacement-history, and check if this helps?

Many thanks,

Seismosoft Support

[isuste]

Dear Seismosoft,

I have tried the same model with a lower (1/1000) displacement history. I am actually getting a response but it does not seem to make much sense.

I have uploaded the shape of the used (scaled x10) displacement history curve here: http://dl.dropbox.com/u/1052773/loading ... scaled.PNG and the calculated hysteretic response here: http://dl.dropbox.com/u/1052773/respons ... linear.PNG

I hope it is of any help to you.

Best regards,
Iztok

[seismosoft]

Dear Iztok,

We have managed to run your models without problems, using a time-history of the type: 0.002, -0.002, 0.003, -0.003, 0.004, -0.004.

In any case, this query of yours has made us realise that, in the Help System, we have not referenced properly and fully these two response curves. We will evidently correct this fault in the next version, noting that these two hysteretic models have been proposed by:

- M.V. Sivaselvan & A.M. Reinhorn (1999). "Hysteretic models for cyclic behavior of deteriorating inelastic structures." Technical Report MCEER-99-0018, Multidisciplinary Centre for Earthquake Engineering Research, State University of New York at Buffalo, Buffalo, N.Y.
- M.V. Sivaselvan & A.M. Reinhorn (2000). "Hysteretic models for deteriorating inelastic systems." ASCE Journal of Structural Engineering, Vol. 126, No. 6, pp. 633-640.

And would perhaps now suggest you to retrieve these publications (they are retrievable from a web search, along with a number of other publications describing studies where these hysteretic models have been used), and better understand if and how to calibrate the curves' parameters to suit your needs.

Seismosoft Support