
Re: Increase in shaft diameter in pure torsion?
Bill McEachern Nov 24, 2010 6:41 PM (in response to Bryce Engle)Poisson's ratio it gets shorter and fattter when you torque it.

Re: Increase in shaft diameter in pure torsion?
Anthony Botting Nov 25, 2010 12:19 AM (in response to Bryce Engle)It is due to linear extrapolation of the graphing algorithm. Here is a diagram showing why (from SW tech support manual).

expansion.png 43.4 K


Re: Increase in shaft diameter in pure torsion?
Bryce Engle Nov 29, 2010 10:24 AM (in response to Bryce Engle)So this increase in diameter is largley artificial based on how solidworks solves the simulation?
As far as Poisson'sin my model it shows no change in length along the X axis despite a 0.020 increase in diameter (X & Y axis displacement graphs attached).
Also if
Stress = E x Strain & Poisson's Ratio = Strain / Strain, then shouldn't the largest increase in diameter come where stress is the highestthe fixed end of the shaft; not at the free end of the shaft where the torque is applied? Von Mises graph attached
Thank in advance for any additional insight.

stress.jpg 69.3 K

X Axis.jpg 61.2 K

Y axis.jpg 59.5 K
