Bending moment calculation 1

[engsamer]

I want to manual claculate the bending moment ( in-plane , Out-plane) of piping isometric consist of vertical pipe attched with flange and horizontal pipe with elbow which atached to previoud pipe ,what eqyations are used for calculation

 

[C2it]

You could try (force x distance) = moment ?

 

[MiketheEngineer]

You could go back to school.... This is pretty basic - any statics book will explain it,,,

 

[BigInch]

Moment distribution would be suggested, for two "O" beams connected at one end, beams in a horizontal plane with some vertical loads applied to one or both of the beams should do it, appropriately assuming pinned or fixed ends at the other ends of the beams not connecting together, depending on how they are supported there.

What would you be doing, if you knew that you could not fail?

 

[engsamer]

The problem is calculating resulting bending moment due to weight to calculate stress due to sustained load

 

[BigInch]

Dead Weight is considered sustained... unless the pipe is moving between planets.

What would you be doing, if you knew that you could not fail?

 

[stanier]

Get hold of a copy of MW Kellogg's Book Piping Design.

http://www.amazon.com/Design-Piping-Systems-Kellogg-Company/dp/1578988233

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[engsamer]

I attached the pipe isometric if any one could give me bending moment due to weight for every point , as I want to check this data with caesar ii output data
also how to calculate moment loading range to calculate stress due to displacement range

 

[SNORGY]

engsamer,

Kellogg's or LC Peng's books will help with something of this nature.

The isometric gives no indication of what the flange at the one end or the valve at the other end is connected to. You will need to establish the boundary conditions there.

I am amused to some degree by the statement on the right hand side of the isometric:

"DESIGN DATA - COOLING AND EXPANSION EFFECT: NONE".

Looks like someone's already decided that there is not a problem here.

Light-heartedness aside, this would be just like an example problem straight out of Kellogg. See Stanier's post for the link. Good for you to want to do some hand-calculation-verification of computer output. That will ultimately separate you from a lot of other engineers.

 

[engsamer]

the flange is connected to pressure vessel and this to be cosider anchor , the valve is connected to other line and assume to be anchor
so , what is the bending moment at each node

 

[stanier]

Engsamer,

Spend the 18 bucks get the book and calculate it. We are not here to do your work for you!

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[engsamer]

done

 

[engsamer]

I download all the books that related to this subject , but it's all old and based on old techniques and also in English system units only so that the factors are not corrects also No one solve the pipe system in correct manner they are assuming fixed point and start solving and this is totally wrong So Till now I can't find real piping stress Engineer can doing Hand calculation of just simple Isometric they are all depend on Software which is easy and fast but without any background or Engineering depth of how it's works and what kind of equation it used.

 

[BigInch]

Piping usually has a fixed point.
Use the English units and convert to whatever you want.
Structural analysis discusses many hand methods, a number of which are the same used for computer pipe stress analysis.

What would you be doing, if you knew that you could not fail?

 

[SNORGY]

Books such as Kellogg may give the appearance of being wrong or obsolete, but the theory and methodology therein contained are likely still valid.

Computer programs (CAESAR II, CAEPIPE, etc.) do a good job of setting up and solving the matrices and so forth, but the methods still work.

 

[BigInch]

They're just a fancy GUI that makes the interface more comprehensible, but unfortunately while dumbing down the math. In any case, that's what computers are supposed to do. You can still learn a lot about it in structural engineering classes. I don't think that mechanical engineering courses concentrate on that aspect of it. It used to be that pipe stress was a province of structural engineers that had become aclimated to specifying "O" beams.

What would you be doing, if you knew that you could not fail?

 

[stanier]

Suggested reading below, but yes they are in Imperial units as the techniques were developed before Napoleon's thoughts on units were spread across the Atlantic. By the time this occurred the guys at Mare Island had developed computer software to solve piping stress analysis challenges.

Its far easier to convert dimensions and parameters to Imperial units than find the information you seek in SI units.

Piping & Pipeline Design by George Antaki
Piping Handbook Nayyar

Alternatively you could invest in Caesar II, Autopipe, Triflex etc or pay someone who does know how to use the software.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[BigInch]

Information in SI units. Ya similar to hobby horse corprolites.

What would you be doing, if you knew that you could not fail?

 

[engsamer]

Dear all
The main subject is how to calculate piping stress analysis manually then check it using Software such as caesar II , to give you same result
what the equation used in calculation of forces and moments in caesar ?

 

[BigInch]

Google this "Matrix methods in Structural Analysis"


What would you be doing, if you knew that you could not fail?