Torsion load curved beam results in My (Bi-moment?)

[sjefbrands]

Hi,

I have a question regarding the calculation of torsion in curved beam. I have a curved beam with a couple of supports. When i apply a vertical load, the My - moment distribution is what i expected.
When i add a torsion moment load (Mx) the My - moment distribution changes.
I suspect that this is caused by the ‘Bi-moment’ effect, is that correct? Or is there a different effect causing this moment?

Thank you in advance

[karamba3d]

Hi @sjefbrands,
when the orientation of a beam changes over its length, then the moment vector’s components with respect to the local coordinate system also changes. That’s how a torsional moment load can start to produce cross section moments about the local y-axis. Think of a cantilever beam with a 90° bend:

|--------|/////
|
|
^
^
|

– Clemens