Modeling tied expansion joint with lateral movements

Hi,

How do I model a tied expansion joint with lateral movements (required to cater for tank settlement of 40mm). I did followed the application guide and did use the 'Expansion Joint Modeler' and the result is the same, which is an expansion joint that only take axial loading and displacement.

Regards,
Fesh

At nozzle node point take a connecting node & feed the value.
Say node 10 is the nozzle point. support 10 anchor C node 11.
At 11 displacement x=0,y=40,Z=0,rx=0,ry=0 & rz=0

Apreciate your reply, but that is only to input the nozzle displacement.

Modelling the expansion joint is as per instructions in the CAESAR manuals, and incorporating the tank displacement into your analysis is what shr had provided... but your main task is not yet done, you have to check the expansion joint vendor if the lateral displacement resulted from the analysis is within the limits of allowed displacement of the exj.

Goodluck!

40 mm lateral movement requires practically always unit which has 2 bellows elements and pipe between. You have to make sure you have space for such unit.

If you have only axial displacement and loading you can be sure that the model is wrong.

Already did input the tank displacement, but the Expansion Joint Modeler didn't seem to have acknowledge the displacement.

There will be no problem with the actual expansion joint design because it can take up to 100mm of lateral displacement.

As for the modeling, yes, I have modeled it with two bellows with connecting spool in between and a tie rod running through the middle for the axial restraints. The part that got me stuck is how should I consider the restraints, of it's location and type, for it to be able to move laterally.

Thx for your feedback guys.

Regards,
Fesh

Hello Fesh

Exp. joint with tie rods helps to absorb lateral movements and differential settlement occurs in vertical direction. I want to know how do you want to install exp. joint in your case. Regarding modelling of joint in caesar for both the ways u have used lateral movement will be absorbed where as axial load remaining the same due to tie rod.

Rgds
vishwa

Hi Fesh

Have you set your load case W+P1+T1+D1(ope) & W+P1+D1(sus) ?
Do not missed out D1 ( displacement) otherwise it will not show you result as you want.

shr,

Yes I did got the load case right.. hence the very high load at the anchor point.


Regards,
Fesh

That means you do not model your tie rod properly. check caesar manual for that.
Say your bellow end to end node from 10 to 100 in X direction.
Model rid rod 10 to 99. 99 put X Ry Rz with c node 100.

shr,

I believe I have done the model correctly because the loadings are fine before the displacement is considered.

Ok if you want upload your file or send it to habibur21@gmail.com
I shall try to identify the problem.