Hi All,

I used to model vertical pipe support supported into vessel clip but normally we model the rigid all the way to vessel centerline breaking the element at vessel outer diameter so we can differentiate temperature of rigid element between the inside and outside of vessel. The intersection of the vessel wall and the rigid is actually a clip and if we want to evaluate the reactions in this clip, we simply define an anchor and a cnode. I have a request at this time to evaluate this load on the clip and since this bracket is also braced from below (a triangle it looks in the side view) then I decide to model another rigid from pipe support to the bottom clip. I understood it is always to be connected as cnode. I don't know how to attach a sketch here but I can send model if anybody is willing to help and my problem is that the clips are getting very high load - meaning it doesn't make sense to me. If I remove the brace below ((almost 45 deg.) leaving only a horizontal steel (rigid) welded into a clip then I get a reasonable load on the clip. I am thinking there should be a way to model it correctly to evaluate the clip load properly. Please give me any email address and I can send this model.

Please Rich/Dave, I need your help, if you can give me your email address here. Thank you all!

EddieB

U can mail me...niteshmech1@hotmail.com.

Dear,

Loads in you bracket CNode will not be good, as not having an articulated node (you will be modelling a totally fixed node), your bracked will be overloading your clip cantilever.

I will suggest modelling only the clip cantilever, and with your reaction loads, calculate by hand your clips reactions, both bracket and cantilever), depending on your clip constuction, knowing the steel node type. Your bracket will be basically taking a compresion load because of the vertical load.

Regards,

Hi Eddie,

Part of your high loads were due to temperature being set to ambient on the vessel. This is a minor oversight, otherwise your procedure is sound. To reiterate:

Model the vessel with rigid elements. It is best to use a one rigid element at the center of the vessel (anchor this) to represent vessel height and then use another rigid to represent the diameter of the vessel (cnode with an anchor to the rigid representing the vessel center-line). Apply the proper temperature to these nodes. Your brackets can then be represented with rigid elements. These will be cnoded to the rigid element representing the vessel diameter. Connection on the pipe side is up to the specifications.


Cheers,

*EDIT: It is recommended to use a pipe instead of a rigid for the vessel center-line. This way windloads can be taken into account on the vessel.