Simply supported pipe on a support - is this possible?

[dr2234]

Hi,

I am trying to simulate a pipe resting on three supports - the reason i am doing this is that the region directly in contact with the support has thinned, so i need to determine the stresses in the thinned section of pipe.

The pipe is simply resting on the supports and is free to move axially (to allow for expansion). This means that i dont want a bonded contact.

I have tried using frictional contact, but this creates a non-linear analysis which wont converge when i apply a force. The analysis runs when i apply a displacement but this isnt simulating what i need.

Does anyone know of a way of simulating this sort of simple support i.e. purely not allowing the pipe to pass through the support!! I am using ANSYS solver.

Thanks in advance. KLT

 

[racookpe1978]

If there is no restraint to the pipe movement, isn't your problem reduced to the internal pressure problem of the pipe - using the "thinned" wall of the pipe as a limit? There is a slight weight and moment problem, but that will usually be less than than the internal pressure problem ... unless your sag is very large.

(Add more margin for additional corrosion.)

 

[OSIRIS7]

Normally for pipe stress calculations you must have 1 fixed point at which the software starts to calculate. This means that if you need to calculate flexibility you should insert more supports until you find a fixed point. If you are an experienced flexibility calculator you could do without fixed point by assuming one at a point that does not matter nor contribute to your point of interest. I.e. if you have an axial stop somewhere and the next one is a side support, these two may be regarded as a fixed point, if these are not too close to the situation you are inspecting.

 

[TheMotionGuy]

I've only used ANSYS in a long while--not since like ANSYS 5.1, but can't you get a solution by fixing just one end--as this will still allow it to be unconstrained axially? Take for example if there was some thermal expansion, the pipe still expands or contracts, it will just do so from one end.

 

[TheMotionGuy]

*edit*

"Haven't" used ANSYS in a long while.