Definition - What does Torsion Force mean?
A torsion force is a load that is a applied to a material through torque. The torque that is applied creates a shear stress. If a torsion force is large enough, it can cause a material to undergo a twisting motion during elastic and plastic deformation. Torsion force is commonly measured in foot-pounds or Newton-meters.
Mechanical parts such as shafts are so often placed under forces of torsion that material selection is a key consideration to prevent failure.
Corrosionpedia explains Torsion Force
Torsion forces can be found in many different instances. A screwdriver used to twist a screw into place has a shaft that is undergoing a torsion force. Suspension bridges can be subjected to torsion forces when gusts of wind blow them back and forth. Drive shafts, or any type of shaft subjected to circumferential motion, can be exposed to torsion forces.
The amount of torsion force a material can handle is often calculated using a torsion test, which monitors the amount of force applied in torsion as well as the degrees of rotation that have occurred.
Ductile materials are able to plastically deform when subjected to torsion forces. Hard, brittle materials may be able to withstand higher torsion forces, but they are less likely to deform prior to final fracture.