What is TORSIONAL STRESS ?

                   When a shaft is subjected two equal and opposite Torque then stress induced in a shaft due to this torque is known as Torsional Stress.

• Torsional Stress is also known as Torsional Shear Stress.
• It is induced in a shaft due to Twisting of shaft.
• Torsion is also caused, if one end of shaft is rigidly fixed and a Torque or Couple is applied at another end of shaft.
  
• Torsion stress is find by using Torsion Equation.

                               Where, 𝝉  =  Torsional Stress or Torsional Shear Stress induced in shaft

                                            r  =  Radius of shaft

                                           T  =  Torque or Twisting Moment

                                           J   =  Moment of Inertia

                                           C  =  Modulus of Rigidity for Shaft Material

                                           𝜽  =  Angle of twist

                                            ᶩ   =  Length of shaft

• If we use Torsion Equation then following Assumption must be consider :-

1. Shaft material is uniform throughout.
2. Shaft has uniform cross-section throughout.
3. Cross-section of shaft is plane and circular before torsion and remain plane and circular after torsion.

Maximum and Minimum Torsional Shear Stress in solid shaft

Maximum Torsional Shear Stress :- 

Torsional Shear Stress is maximum at Outer surface of shaft.

Minimum Torsional Shear Stress :-

Torsional Shear Stress is Minimum at the Center of Shaft.