how to model base isolation struture

[wangyanan]

Dear sir or Miss,
how can I model a base isolated struture using this software, which element can be used to model isolation bearing?
Thanks for your help!

[huffte]

Link elements are ideal for modeling base isolated structures,wangyanan. And there are several options available depending upon which type of isolator you wish to model.

If you'll open SeismoStruct Help and go to the "Element Classes" section, you will find a sub-section called "Link Elements - Link".

The Help System is quite good in describing the correct method of defining a link element. Four nodes are required, with the first two being initially coincident.

For friction-pendulum isolators, you might try the plastic ('plst') link. For lead-rubber-bearing systems, I have had success with the bilinear kinematic hardening element ('bl_kin'). As you will see in the Help System, there are many other options as well.

Modeling base-isolated structures in SeismoStruct is very convenient wangyanan.

Best of luck with your work.

[Fiona Dong]

Hi,huffte. I had used bl-kin to model the lead-rubber-bearing. And I want to know how to link the node and the base? I want to model a base isolated structure. I've tried many times, but there's something wrong.
Thank you for your help!

[huffte]

Fiona,

I will send the following models:

1. A simple SeismoStruct model which consists of 20 independent isolation devices – Model-Isolators-LRB-NMSZ-Artif.spf
2. A slightly more complicated model of a single bridge pier with an isolated mass on top – Pipe-Pile-Bent.spf
3. A complete bridge model with isolated bents and abutments – SR-114-Isolated

I recommend that you go through these in order - the degree of complexity increases each time.

Basically, you will need a node at the bottom of the isolator which is connected, for example, to the top of a bridge pier.

You will need a second node which has the exact same coordinates (initially coincident) as the first node.

A third node defines the 1-1 direction of the isolator, and a fourth node defines the 1-3 plane (See the SeismoStruct Help System).

I hope the models I have sent to your e-mail address along with the excellent discussion in the Help System help you to better understand the modeling of isolators in SeismoStruct.

Best of luck, Fiona.

[Fiona Dong]

huffte, thanks a lot. I have received your e-mail. I will study it. Thanks again for your help.

[dpucci]

Hello,
I am modelling base isolated structure using link elements. Could please anyone send me any model with base isolation to see how to model or suggest me any work on this topic?
Thanks a lot.

[huffte]

I have sent 3 models to your e-mail address as listed in the forum info dpucci. I hope these help.

Model-Isolators-FPS.spf (Friction-Pendulum-System-based link properties)

Model-Isolators-LRB.spf (Lead-Rubber-Bearing-based link properties)

SR114-Isolated.spf ( a complete bridge structure with link isolators at all bearing locations)

Best regards and happy modeling.

[dpucci]

Hi Huffte,
thanks a lot for your help!!!

[Muntasir]

Dear Hufte,
Thanks for your support for the seismostruct users. Would you please send me the above mentioned three isolated models.

Regards
Muntasir

[huffte]

Hi Muntasir. The models have been sent. Best of luck and keep us posted on the forum regarding new ideas on isolation models.