Torsion load on hollow shaft

[jh149]

I am new to I-DEAS FEA. Can someone teach me how to add a torsion load constraint onto the tip of a hollow shaft?

 

[feadude]

The question is not clear? Which one load or constraint?
Start with making a cylindrical coordinate system. May be that helps.

 

[jh149]

I just want to add a torque (or z-moment)to a hollow shaft that is not uniform in cross section (so I can't use beam element). So what do I do after creating a cylindrical coordinate? I am using the 3D free mesh, I fully constrained one end and applied a z-moment at the centerpoint of the other end, when I solve problem, everything show up as 0 (stess, deflection...)

 

[feadude]

If you applied a z-moment at the centerpoint of the other end, since that point is not attached to any elements you will get all zeroz. Even if it was a solid shaft and you apply a torque on center point if you are using solid elements you will still get all zeros since solid elements do not support moments. The way this should be done is to split your loading surface into two equal surfaces and then apply two equal distributed line loads perpendicular to split surface dividing edges, in effect create a torque using a COUPLE of equal but opposite in direction line forces. the magnitude of these loads is determined by dividing torque by midsurface diameter [(ID+OD)/2] of hollow shaft I am hesitant to say apply two equal but oppositr in direction point loads but point loads are usually trouble makers.

 

[jh149]

It works! Thanks a lot!