In torsion, the center of the bar contributes little to the torque, as it has no leverage (radius from axis of rotation). That is why a solid bar is only a little better than a hollow bar of the same diameter, for torsion. For bending, actually I believe a hollow bar is much easier to bend than a solid bar...
Link to some info on the subject:
http://www.hotchkis.net/pdf_files/HollowSwayTech-D.pdf
Quote:
|
Originally Posted by Thunderchicken
That may be true when the bars are in bending (axial). But for torsional loads a solid bar is better.
|