What is shear stress in a torsion bar?

Torsion in solid mechanics refers to the twisting of an object caused by an applied torque, resulting in angular deformation. The resulting torsional shear stress is commonly expressed in pascals or pounds per square inch. In circular shafts, this shear stress acts tangent to circles centered on the shaft axis.

What we know

• Torsion is defined as the twisting of an object caused by an applied torque, representing an angular deformation measured by the rotation of a cross-section. [1, 2]
• Torsional shear stress resulting from torque is expressed in units of pascals or pounds per square inch. [2]
• In circular shafts, shear stress is tangent to circles centered on the axis of the shaft. [2]
• For non-circular cross-sections, twisting is accompanied by warping, meaning transverse sections do not generally remain plane. [2]

Where to go next

• how it workedHow is the torsion constant calculated for different cross-sections?
• what caused itWhat role does shear modulus play in material twisting?
• the bigger pictureWhat are mechanical stress and strain in continuous media?
• a case in pointHow do closed-form solutions apply to thin open and closed sections?
• how we knowWhat methods are used for analyzing general non-circular sections?
• an unexpected connectionHow do reference books like Roark's Formulas compile stress equations?Engineering design manuals compiled over decades provide the practical formulas used to calculate complex stresses like torsion bar shear.

Sources

• [1]torsion (Wikidata Q826575) · CC0 1.0
• [2]Torsion (mechanics) · CC BY-SA 4.0
• [3]Torsion constant · CC BY-SA 4.0
• [4]Roark's Formulas for Stress and Strain · CC BY-SA 4.0
• [5]Stress (mechanics) · CC BY-SA 4.0