Ansys beam element torsional stress

[AW2011]

Hello everyone,

Is it possible to extract the shear stress due to torsion from the Ansys beam 188 element? I have created a simple case in which the cross section is an I-beam. One end is fixed while the other end is subjected to a moment leading to torsion. I can see that the I-beam deforms in the expected way, but the shear stresses are zero. The Beam tool does not have a shear stress output either.

Or is it not possible to use beam elements for torsion?

Regards,
AW2011

 

[petb]

Hi,

Sorry to answer your question with a question, but here it goes: are you applying torsional loads large enough to partially yield the cross-section? If so, beam elements like 189 are not very well suited for that. The re-distribution of shear stresses are not captured during the analysis. If that's the case you're better of using shells or solids.

/petb

 

[AW2011]

Hi petb,

thanks for your reply.

I have just replaced the I-beam with a circular cross-section (because I wasn't sure what torsional loads would cause an I-beam to yield). I have applied a small moment at one end such that the beam should remain in the elastic regime. So I have hand calculations to show what the maximum (elastic) torsional stress should be ( around 100 MPa), and I am trying to see this on workbench. However, the shear stresses displayed are all very low (around 0.01MPa).

I read that beam 188/189 have torsional capabilities. But must I key in some APDL command to visualize this on workbench?

Regards,
AW2011