Torsion

In the previous chapters, the behavior of beams subjected to axial and transverse loads is studied in detail. In chapter 6, a fairly general, three dimensional loading is considered, with one important restriction: the beam is assumed to bend without twisting. Twisting, however, is often present in structures, and in fact, many important structural components are designed to carry torsional loads primarily.

Power transmission drive shafts are a prime example of structural components designed to carry a specific torque. Such components are designed with solid or thinwalled circular cross-sections. Numerous other structural components are designed to carry a combination of axial, bending, and torsional loads. For instance, an aircraft wing must carry the bending and torsional moments generated by the aerodynamic forces.