Lecture - 11

1. Lecture - 11 Torsion Objective:- • Discuss behavior of torsional loading on a long- • circular straight member such as shaft or tube. • 2) Calculate the torsional stress, deformation and • strain. Notice the deformation of the rectangular element when this rubber bar is subjected to a torque.

2. Angle of twist 

3. Shearing Strain / Angle of twist

4. Shearing Strain  The shear strain for the material increases linearly with , i.e.,  = (/c)max

5.     Summary: When torsion applied to a member, it causes only shear strain and shear stress. T →  →  Shear strain varies linearly from zero at shaft center to a maximum value at the surface such that: Shear stress varies linearly from zero at shaft center to a maximum value at the surface such that: When torque is applied to the shaft it does not change its length, it only rotates its plane with an angle , called angle of twist which is maximum at the face end.

6. Torsion Formula Where,

7. Polar moment of Inertia J Solid Shaft.

8. Polar moment of Inertia J Tubular Shaft.

9. Procedure for Analysis; • Internal Loading. ( Ti using static's) • Section Property. ( Ci, Co, J) • Torsion Formula.

10. Figure Example:

11. Solution:

12. Example:

13. Solution:

14. The enD