Why are the internal stresses in thermal pipelines and the thrust at the fixing points independent of length?
Thread Content
Multiple publications state that the stresses acting on thermal pipes and the thrusts at the fixing points depend only on the pipe material, temperature, and wall thickness, and are unrelated to the length. I can’t understand this: with the same material, temperature, and wall thickness, and before they are fixed, one is long and the other short – is the thrust exerted on the fixing points the same in both cases? This is a bit hard to understand
Where have all the people on the forum gone? There’s a serious lack of activity
Which book states this? Come and take a look here.
The thermal stress calculation formula does not include length
I don’t know this, but I can’t figure it out
You’ll understand if you look at the derivation of the formula
Take a look at the formulas for thermal calculations in mechanics of materials; the length of the material is omitted in those formulas. Theoretically, that’s the case, but as the tube gets longer, its stiffness decreases, which leads to deformation and a reduced heat transfer.
Think about it: compressing a 1-meter-long rod by 100 mm versus compressing a 2-meter-long rod by 200 mm – if the stiffness of the rods is the same, will the force F required be the same? If the force is the same. It’s easier to understand if it has nothing to do with length.
I’ve been learning; over the weekend I read the posts from various seniors on the forum and learned a lot. Thank you