Tension influence on torsion in a pipe
Tension influence on torsion in a pipe
(OP)
Hi all,
A string of pipe elements clamped one side and loaded with a torsion moment results in a certain amount of rotation. Now I'm wondering if adding a tensile force to the pipe's free end results in a lower amount of rotation.
I tried to simulate this very simple problem in Ansys but rotations were equal with and without a tensile force.
Is this correct and are the two loads not coupled in any way, or am I doing something wrong here?
Thanks in advance
dersman
A string of pipe elements clamped one side and loaded with a torsion moment results in a certain amount of rotation. Now I'm wondering if adding a tensile force to the pipe's free end results in a lower amount of rotation.
I tried to simulate this very simple problem in Ansys but rotations were equal with and without a tensile force.
Is this correct and are the two loads not coupled in any way, or am I doing something wrong here?
Thanks in advance
dersman





RE: Tension influence on torsion in a pipe
I suppose the rotation ist identical in both load cases, because of the linearity assumption. Are you tanking acout of stress stiffening and/or prestress in your simulation?
Regards,
Alex
RE: Tension influence on torsion in a pipe
what linearity assumption do you mean? To answer your question, yes I tried both prestress and stress stiffening, both didn't change the results. The manual says about stress stiffening that it only couples bending stiffness and axial stiffness. Because there is no bending in my simulation I think stress stiffening has no effect.
dersman
RE: Tension influence on torsion in a pipe
U(L1)+U(L2)=U(L1+L2)
This is only true for linear systems with small displacements.
You see, there is perhaps nothing wrong with your simulation, if the displacements are small.
Regards,
Alex
RE: Tension influence on torsion in a pipe
Do you agree with me that adding a tensile force should result in fewer rotation?
I understand that when you add the results of 2 seperate runs, one with torsion and one with tension, the end result will be the same amount of rotation as the run with torsion only. I just thought there would be some kind of coupling between tension and torsion.
RE: Tension influence on torsion in a pipe
Hope it helps!
Regards,
Alex