Flatsliderbearing for 2d 2dof model

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cgtydmrc
Posts: 61
Joined: Mon Dec 01, 2014 7:04 am
Location: United Kingdom

Flatsliderbearing for 2d 2dof model

Post by cgtydmrc » Tue Jul 25, 2017 7:45 am

Hi,

Could you please help on what is the possible way to include base isolator (for example, flatsliderbearing) into a 2d 2dof model?

Thanks,
C.

Jhno
Posts: 214
Joined: Sat May 05, 2012 2:55 pm
Location: Laval

Re: Flatsliderbearing for 2d 2dof model

Post by Jhno » Tue Jul 25, 2017 8:15 am

Zerolength element ?

cgtydmrc
Posts: 61
Joined: Mon Dec 01, 2014 7:04 am
Location: United Kingdom

Re: Flatsliderbearing for 2d 2dof model

Post by cgtydmrc » Tue Jul 25, 2017 8:50 am

I know I can use zero-length element or two-node link element with a finite length. However, the problem is while all the nodes in my model are 2dof, the nodes that I connect a flatslidebearing element require to have 3dof. Therefore, my question to you is that have you ever utilized flatsliderbearing element in a 2d 2dof model before?

Thanks.

selimgunay
Posts: 634
Joined: Mon Sep 09, 2013 8:50 pm
Location: University of California, Berkeley

Re: Flatsliderbearing for 2d 2dof model

Post by selimgunay » Thu Jul 27, 2017 10:16 pm

You can use it for a 2D problem, please see the descriptions and examples in the below link

http://opensees.berkeley.edu/wiki/index ... ng_Element

cgtydmrc
Posts: 61
Joined: Mon Dec 01, 2014 7:04 am
Location: United Kingdom

Re: Flatsliderbearing for 2d 2dof model

Post by cgtydmrc » Fri Jul 28, 2017 6:27 am

Selim hocam merhabalar,

My models consist of 4 node quad elements with 2 dof per node. However, the flatslidebearing element requires the nodes to have 3 dof. That is why it creates a problem when i try to place the bearing in my model. To connect two different models (for example 2d 2dof and 2d 3dof) I employed equal degree of freedom multi-point constraints. I believe it works in the same way, but is there an other way that this bearing element works also in a 2d 2dof model?

Thanks in advance,
Cagatay

selimgunay
Posts: 634
Joined: Mon Sep 09, 2013 8:50 pm
Location: University of California, Berkeley

Re: Flatsliderbearing for 2d 2dof model

Post by selimgunay » Mon Jul 31, 2017 11:20 pm

Cagatay merhaba,

I think you can fix the rotational DOF. It seems this is what is done in the examples in the wiki page.

http://opensees.berkeley.edu/wiki/index ... er2d_2.tcl

cgtydmrc
Posts: 61
Joined: Mon Dec 01, 2014 7:04 am
Location: United Kingdom

Re: Flatsliderbearing for 2d 2dof model

Post by cgtydmrc » Tue Aug 07, 2018 6:45 am

Selim hocam merhabalar,

I modelled the bearing element in the way I explained above and it gives a warning such:

WARNING FlatSliderSimple2d::setUp() - element: 300 - ignoring nodes and using specified local x vector to determine orientation.
WARNING FlatSliderSimple2d::setUp() - element: 301 - ignoring nodes and using specified local x vector to determine orientation.
WARNING FlatSliderSimple2d::setUp() - element: 302 - ignoring nodes and using specified local x vector to determine orientation.
WARNING FlatSliderSimple2d::setUp() - element: 303 - ignoring nodes and using specified local x vector to determine orientation.

And it gives a structural period of 7.86 seconds for the first 5 periods same. The fundamental period of the building was 0.29 s without the slide bearing element. Do you think this is okay? Or too much difference which happens because of a wrong assumption in the model?

Thanks,
Cagatay

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