How to model concentrated hinges

[PhungNgocDung]

Hi Seismosoft,
I am trying to model a frame with concentrated hinges located at critical sections of RC-frames. I want to test the Takeda model of RC elements. I would like to ask how to couple 1point-Link and elastic frame elements? (I have carefully read the manual but there is no instruction for doing that)

[seismosoft]

Dear PhungNgocDung,

We are not quite sure we understand the difficulties you seem to be experiencing, but we will give it a go, in any case, with an example:
- define nodes A(0,0,0) and B(0,0,3)
- define an elastic element going from node A to B
- define node AA(0,0,0)
- define a link element, with an associated Takeda response curve, going from node AA to A.
- define node BB(0,0,3)
- define a link element, with an associated Takeda response curve, going from node B to BB.

Seismosoft Support

[PhungNgocDung]

Dear Seismosoft,
Thanks for answering my questions. I also did the modelling as the ways you mentioned. However, the problem is that Link elements and elastic frame elements work independently. With grandually increasing loads, when the Links reach their plastic moment resistance, the moments in elastic frame elements (at link positions) are still able to carry more loads. So the links and elastic frames are not coupled together.
Thank you.

[seismosoft]

Yes, of course, you will need to calibrate the elastic element properties in order to render them "compatible" with the link elements.

In alternative, you may also consider using plastic-hinge specialised software, such as Ruaumoko, Drain, Idarc, etc.

Seismosoft Support