1-Visitor

Question

Pipe Thrust Forces

Forum|Forum|11 years ago
September 19, 2014
5 replies
9029 views

I know Lusk recently posted some files on this, but it was not really what I was looking for. I am trying to be able to generate a table of thrust forces at select junctions in my pipeline. Currently, it is set up for one pressure, but I want to evaluate multiple scenarios in this sheet. Pressure for steady state, test, surge (e.g. 20, 50, 35). The middle one only has a static component, but the others require analysis. The other problem I need to figure out, may be a programing issue, is the restraint for a dead end. The X component using 90 degrees is correct; however, you plug in 0 for your angle and the result is 0. Functions, programming, etc. are all fair game. I'd like a CSV dump to send to a spreadsheet when all is said and done. Your help is greatly appreciated in

1_Thrust0-xmcd.zip

Statistics_Analysis

E

ELSID

Author

1-Visitor

Worked on the file last night. Here is my latest file.

MathCAD 15 M030

1_Thrust1-xmcdz.zip

L

Lev

1-Visitor

Beta of zero degrees means a straight pipe. Where will the thrust come from?

F

Fred_Kohlhepp

23-Emerald I

For situations with no flow (velocities = 0) there should be no external forces--pressure causes stresses and strains, but there are no unbalanced forces.

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ELSID

Author

1-Visitor

Fred, not no flow...no angle, as in a dead end. I think this needs to be a program loop. If b=0 only PA applies.

I think that this whole sheet can be made into a function with a program loop.

M

MikeArmstrong

1-Visitor

ELSID wrote:
Fred, not no flow...no angle, as in a dead end. I think this needs to be a program loop. If b=0 only PA applies.
I think that this whole sheet can be made into a function with a program loop.

Or you could add this condition to F.sx and F.sy for simplicity.

Putting the whole sheet into a program loop will make it very complicated and difficult to check. The current layout is the better option IMO.

M

MikeArmstrong

1-Visitor

ELSID wrote:
I'd like a CSV dump to send to a spreadsheet when all is said and done. Your help is greatly appreciated in

Can you use WRITEEXCEL function for this?

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ELSID

Author

1-Visitor

I posted THRUST3 earlier today. Do I need to set up a counter to extract the scalar value of the angle? Seem illogical but I am confused.

Mike, I did not understand your response above with "you could add this condition to F.sx and F.sy for simplicity"

Please attach file or sample.

Thanks

M

MikeArmstrong

1-Visitor

Ok. I have just looked at your sheet and a littkle confused.

You have 4 values for beta which are assessed. F.sx is dependant on beta, but both p and A are single column vectors, so when you have the condition 'if beta = 0' return p*a - are you trying to return the corresponding value of p*A?

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ELSID

Author

1-Visitor

That is SO funny. I my revised sheet from last night does the same thing. That was the reason I was asking about setting up the counter in the post above!

I will continue with my calculation and post when done. Glad to know I was on the right track as I have not touched the vector maths in a long time ... just wish the programing was a little easier for a checker.