Thanks again BigInch,
So the F.E.M is merely 6 EI?/L alone?
I think I get the statical indeterminacy and obtaining the displacement ? as a result of the thermal expansion as well as the thermal expansion force is very easy
I was confused into thinking maybe i needed to use F*L and 6 EI?/L
So...
>>You must first calculate the fixed end moments due to those displacements and rotations, then simultaneously solve for the amount of the combined rotation which will be equal on both members.<<
Thanks BigInch, I hear you.
I want to use the moment distribution method you mentioned to...
Hello again guys
I'd like to beg your indulgence once again on what I thought I had down pat regarding forces and moments acting at end anchors of an L configuration
I have to use the thermal expansion force at the elbow of the L to obtain moments at the end anchors and I'm getting confused...
Again , thanks very much BigInch.
I downloaded an evaluation version of CEASAR and I'll try it to see if I can figure out how to use it to obtain obtaining the thermal neutral points. I've used used other software to analyze mainline pipe, I'm only recently slowly getting involved with pipe...
Thank you very much BigInch
On the Thermal Neutral Points: .
If we have a straight line, I suppose it would be reasonable to assume the mid point.But if we have a line of say 5 miles with bends and corners, these may be at any point.
Or would it be reasonable to assume they are at the mid...
Hello Guys, its me again.
Once more I apologize for any inconveniences, I've checked the FAQ and I don't think this question has been asked before.
Please what would be "Thermal Neutral Points" in a pipeline (laid directly on the ground but to be to be anchored at intervals . Please, I would...
Thanks BigInch
The approach of canceling out of expansion forces on interior anchors is what I am a bit wary about. If this is the case, I don't even understand why even use anchors at all in the interior as guides alone would appear to be sufficient.????
Thanks
Thanks guys for all your answers so far and I've attached a sketch of the conceptual problem.
In Scenario( A) with Bends/corners between the anchors, its not going to be much of a problem since the bends will relieve the stresses. I believe I will only calculate the anchor force (using the...
The actual amount of the forces I have indicated are hypothetical. I'm wondering if we can consider the forces on either side of the anchor cancelling out and then obtaining a resultant force of zero on an anchor?
What I've seen is people subtracting the forces on either side of the anchor...
Hi raccokpe,
I can assume the deadweight is negligible , i.e supported by the ground between anchors and the force is from expansion/contraction
Its an hypothetical question to gain insight into how to allocate the forces over the anchors.
Sincerely
Hi,
I'm not sure I get the gist of your question and I'm quite unfamiliar with Australian codes, but I've used API 1102 quite a bit and have always used 0.72 as my design factor, but then I was designing according to ASME 31.4 for liquids
It may be that 0.9 may be O.K for gas , but I very much...
Hello Pipeliners,
Hope I can ask what must be a very basic question regarding anchor forces where I have a number of anchors restraining a line.
Suppose I have say four Anchors as shown below and I calculate anchor forces due to thermal and pressure expansion and find this to be say50lbs for...
2. If both ends are anchored the force due to say thermal expansion is calculated as A*E*strain. Would this force be fully on each anchor or would it be half of this force on each anchor?
<Anchor F1?>--------Force=say 1000KN------------<Anchor F2?>
Looking at this , I'm thinking the...
Opps, sorry, I didn't realize you already posted I.see you answered the first part of the question already and that there would be no forces at the one restraint. Thanks, very much.
But on the second part of my last post; would the forces be half at each anchor or the full forces at each...
1. So the pressure force would be Sh*(0.5 +/- ?) depending on if the pipe is expanding or contracting?
2 I hope you don't mind that like Oliver Twist, I keep asking for me. I'll try and do a better job of clarifying. If a pipeline segment is anchored at two ends, stresses would develop. If...
Again thanks BigInch.
>>If the pipe's ends are not restrained, the pipe would simply shorten without any effect on stress, similar to a pipe becoming colder and shrinking in length, which does not create any longitudinal force, if the pipe is free to contract.<<
What if the pipe is fixed at...
I did a little more research. The forces will be opposing each other, so apparently, I have to subtract. If the lengths are symmetrical, they cancel out and ideally become zero.
I'm not yet satisfied with the pressure force formulae and will research it some more
Thanks BigInch,
You're correct and its clear, especially as I talked to a mentor.
The design for the casing (sleeve) is similar to the carrier piper except that the casing (sleeve) will carry the external loads only (dead and live loads )and not the internal pressure.
Pls if you don't mind...
Hello again members,
I have another question if you don't mind
I've in the past designed carrier pipes for road crossings using API 1102 but not designed the sleeve or the casing itself.
I'm wondering how the casing/sleeve is different from the carrier pipe?
Your answers would be very much...