## An Introduction to Uniform Torsion in Cylindrical Shafts

In this tutorial, we introduce torsion. This is simply a bending moment applied about the longitudinal axis. Torsion will cause twisting about the longitudinal axis and is a very common form of loading. Our starting point will be to explore the concept of strain as it applies to circular bars and to derive an equation that relates the strain to the angle of twist in the bar. Next, weโll tie shear stress into the story and see how it relates to applied torque and torsional deformation. Finally, weโll bring everything together with some numerical examples to demonstrate how to deploy the equations weโve developed.