Here is the destabilizing force, in my opinion. If the pipe deflect, a torsional moment appear. As we do when we talk about stability, we can see that torsional moment as a loss of torsional stiffness. If M0 is big enough, the torsional stiffness of the pipe becomes 0 and we have instability...
Thank you for the answer KootK, I agree with every thing you said. Obviously, having big torsional and flexural rigidity, the LTB does not happen for pipe. As I said before, I want to study the problem of particular structures where there are very long pipe (effective length of 50m or more) and...
Omg, I understand that a I section is subjected to LTB and, in general, not a pipe. Thank you for the pictures. I asked for a mathematical analysis, starting from the equations of a beam and searching a condition where the total potential energy is maximum (if it is possible to find that...
Retired13,
I used this:
X orizontal
Y vertical
Z axial
So, I was correct, in that point I talked about x.
Indeed, the moment Mx (which I talked about in my example) is a flexural moment in the x direction, wich generate a deflection in y.
This is my point. In literature, I find pretty easily the analytical description of lateral torsional buckling for open cross section subjected to constant flexural moment: the buckling moment (in a section without warping, as a pipe) is proportional to the square root of the moment of inertia...
Retired13
The ball on a dune is in a point of unstable equilibrium. The equilibrium is stable only in the points where the total potential energy is minimum. Why? If a body (in a minimum point of total potential energy) change his position, the kinetic energy must decrease (because the total...
robiengIT
Oh, I missed the attached file, I'll read it as soon as I can
Klaus
Yes, of course I know the difference, I've studied the problem of lateral torsional buckling during university (in the case of open cross section). But we called "lateral torsional buckling" as "laterale buckling"...
Thank you retrograde, but that page report information about rectangular hollow section, not about circolar hollow sections. I'd like to find the formulation for circolar hollow sections
Yes, I know, I agree. But, is it possible to explain it with math? I studied the buckling behavior of thin walled beams with open cross section, but not of beams with closed cross section. Is it possible to prove analitically that lateral buckling doesn't occur in pipe?
