1. ENGR 220 Section

2. Torsional Deformation of a Circular Shaft

3. Torsional Deformation of a Circular Shaft

7. The Torsional Formula
If the material is elastic then Hooke’s Law applies.

8. Derivation of the Torsional Formula

9. Torsional Equation

10. Lecture Example: Plot the torque on the shaft as a function of position from E to B. The smooth bearings at A and B do not resist torque.

11. Lecture Example: Plot the shear stress distribution acting along a radial line lying in the region EA of the shaft. The smooth bearings at A and B do not resist torque.
Shaft ID = 1 in
Shaft OD = 1.25 in

12. Power Transmission

13. Lecture Example: The gear motor can develop 1/10 hp when it turns at 80 rev/min. If the allowable stress for the shaft is τallow = 4 ksi determine the smallest diameter shaft to the nearest 1/8 in that can be used.