ABSTRACT
The torsion of shafts appears in a number of different branches of engineering, including propeller shafts for ships and aircraft, shafts driving the blades of a helicopter, shafts driving the rear wheels of an automobile and so on. If the shaft is overstressed due to torque, so that the maximum shear stress in shaft exceeds the yield shear stress of the shaft's material, the shaft can fracture. This is an undesirable phenomenon and normally it should be designed out, hence the need for the theory contained in this chapter. Torsion is also important when a rolled steel joint is connected to another rolled steel joint which is at right angles to it, and out-of-plane. This chapter shows to: define torque, prove that and perform practical calculations, understand flanged couplings and perform practical calculations on them. It also shows to: understand close-coiled helical springs, appreciate elastic-plastic torsion of circular-section shafts, understand torsion of thin-walled open sections and perform practical calculations on them.
