I have a question about calculated load on individual restraints on vertical line.

* Figure:
There are 2 anchors in vertical line. One is placed at the bottom of line and the other one is at the top of it. In the middle of pipe, expansion joint is applied.


* My thought is..
1. Calculated load on the bottom anchor should be bigger than top one(anchor).
Bottom and top anchor has different elevation: they have different height. That’s why I think they should have different load calculated by different height.
I tried to figure out this with fluid density and without it. Howerever, i have got same result: each loads are shared same on bottom and top anchor.

2. What I found is CAESAR II just calculate load on restraint and apply same load to each restraint without height concern in case of vertical line. Am I right?


Thank you for your answer in advance.

Caesar is calculating elemental loads the only way it can, by considering everything you tell it that acts between nodes. Fluid weight in a vertical line is always a tricky one, since Caesar (and every similar software package) cannot know that the fluid weight alone acts elsewhere.

The same applies to, for example, a vertical line onto a pump nozzle where the fluid weight acts on the pump casing and not on the nozzle flange.

You can easily modify your model to accommodate this, but you should also be aware of it.

Silji7

If you imagine that these two sppoorts are replaced by two springs with a same spring rate, you can have a same conclusion as Caecar. Spports are kind of spring with a large spring rate.

Actully, since the pipe expansion, the two supports take different loads or only one support take whole load, so a spring support could be used for one of supports in this siuation.

Carter