Stacked pipes. Load to upright supports. 1

[MarioGr]

I have a situation where some pipes need to be stacked 7 rows high by 6 pipes across. Each pipe weighs approx 50kg.

They're stacked on top of each other. Now if this container held soil or water the loads to the uprights would be easy to calculate but in this case I'm unsure how to proceed.

Obviously if the supports were t0 be removed the pipe stack would collapse. It follows that there is a horizontal component of the load at some point on the uprights. Again if this were soil or water there would be a triangular distribution and the centroid of the load would be 1/3 up from the base. From there it would be easy to calculate the moment.

Can anyone here help? Thanks in advance.

 

[1503-44]

No you probably won't be stacking pipe that high. Stacking most steel pipe more than 7 or 8 layers, or just 3 or 4 for large diameters, will start to make them permanently oval shaped and cause way too much work to reshape the ends so that they could be welded together. Very little misalignment in the pipe wall can be tolerated when welding. It is easier when they are perfect circles. Ovals don't work.

 

[Settingsun]

Out of interest, how did your final design value compare to hydrostatic pressure based on the equivalent/average density?

 

[1503-44]

A has 42 pipes. B has 44. Now you have to do it all over again.

 

[Enable]

1503-44: I feel you're being a little too snarky here. Certainly from a practical perspective the design will likely far exceed any theoretical load we would conjure up, but that doesn't make the entire enterprise a useless thought experiment! Hell, KootK would have wasted most of his time on this forum if all we cared about was what to do rather than a deeper understanding of the why. In this case, maybe a deep understanding cannot / is not to be had (probably true), but it's worth at least remarking about rather than simply saying "steel beams NEXT!!"

Anyways, I agree that the induced thermal loads as well as momentum loads caused by...things (someone drops a pipe into the perfect triangular stack and it all rolls to one side, people hit the post with a piece of machinery and the deflection causes momentum of the stacked pipes to form, etc) will probably govern. And yet these are not easy to get a handle on. Because of that I'd design the post not for the pipes but rather some sort of nominal impact load at the extreme end due to the type of equipment that is loading the pipe rack.

As far as the static horizontal load is concerned, I'd probably visualize it as a bunch of slip planes on a stable base and decompose forces along those planes into the horizontal component to get the reaction on the wall. Picture attached. Fair warning I haven't put a whole lot of thought into this (well because 1503-44 is kind of right this rabbit hole aint worth going down too much lol) so I may have done something stupid with this.

 

[MarioGr]

Who's being snarky? I asked a question out of curiosity and you're saying 'Geez wheres my FEA program.'

Don't want to help? That's fine. Scroll on.

 

[Enable]

MarioGr: I specifically bolded the name of the person I was referring to, which was 1503-44. To be crystal clear I was calling him snarky and not you. Now I'm referring to you....notice the bolded name in front of this text. Also, did you not notice the rest of my post where I even took the time to upload a picture of a little schematic I drew...I talked about impact loads due to machinery...

 

[jimstructures]

MarioGr:

If you are going to use this very valuable resource you had better develop a thicker skin which respect to comments and answers on this site. Some of the responses can be very snarky or direct in their replies. Use what you can and ignore the rest. That doesn't mean you shouldn't respond when somebody misunderstands your replies, but remember this is an international site many replies are relatively loose in there use of the Queen's English grammar and spelling.

Jim

 

[1503-44]

OK. I'm not snarky. Its my too dry sense of humor. Nothing personal.
I'm also sensitive to these issues. The first time I ever took a beating was for designing a pipe rack, with shear and moment diagrams and all. I was proud. I did not use "common sizes". My boss said, W10x33 beams, 8x24 columns. Write it down and turn it in. We have to learn to be practical. It stayed with me.

Rabbit holes never have doors, so enter at will.

 

[MarioGr]

Apologies Enable. I misread who your post was directed to.

Again thanks to all.

 

[dik]

I took it as humour and thought it was a cute reply... I was going to add, "...a nice set of pipes, and nicely stacked."

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[daffydemon]

LittleInch (or anyone else): are you able to give further details of the 'famous' reference the pipe stacking calculations were taken from? If the case described by the calculations is the same as mine (which I believe to be the case) I need to include the reference in my report, or show the full hand calcs.

 

[1503-44]

See deformation in vertical direction

https://www.engineersedge.com/calculators/circular_ring_stress_and_deformations__15423.htm