**Introduction**

Watch the below introductory video on torsion and how it is exploited in many mechanical devices as a means of transmitting power. The video also establishes the sign convention and notation we will be using in this course related to torsion.

**Learning Objectives**

By the end of this unit, students should be able to…

- Describe the shear stress distribution within a circular shaft under torsion
- Apply the torsion formula to calculate shear stresses under torsion
- Calculate angle of twist and relate calculation to Hooke’s Law
- Solve for stress and displacements (angle of twist) in statically indeterminate torsion problems
- Explain why the torsion formula is not applicable to non-circular shafts
- Explain the concept of shear flow
- Calculate shear flow and angle of twist for thin walled closed section tubes

#### 3.1 Torsion of Circular Shafts

#### 3.2 Statically Indeterminate Problems

#### 3.3 Torsion of Non-Circular & Thin-Walled Shafts

#### 3.4 Summary and Further Reading