Why in pure tortion of a round beam one diameter increases in size. In theory it shouldn't. I just put a torque on one side and fixed constrained another end. Is this due to the way, how inventor solves it? Is there a way to minimize it?
This thread provides a good explanation:
Basically, it's just an artifact of Inventor's scaling methods. Displacement scaling is not equivalent to increasing the torque on the part.
In "theory" are you saying that the shaft diameter should not expand? What theory are you using?
If you are having a problem with the way Inventor displays this, you can change the scaling to "Undeformed" if you don't want to see the deformation.
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Well, that is the definition of pure torsion. In theory of pure tortion, each cross section along z axis is exposed to the same momentum and deplanation doesn't occure.
Well, now I think that Inventor does it in reality, not theoretically.