Write about torsion of Shaft and their torsion equation?

Torsion of Shaft:-

To transmit energy or power by rotating shaft a turning force is applied at any suitable point at some distance from the axis of shaft and in the plane of transverse cross section. The product of turning force and perpendicular distance between point of application of this force and axis of shaft is known as torque or twisting moments, it is said to be in pure torsion. Due to this torsion shaft exhibition a tendency of shearing off a every cross section perpendicular to the longitudinal axis.

Torsion Equation:-

        T    =   τ   =  CӨ 

        J          R        l

Where,

  T= Torque

   l= Length of Shaft.

   R= Radius of Shaft.

   Ө= Angle of twist.

   C= Modules of Rigidity.

   J= Polar moment of inertia of shaft.

Polar moment of inertia of a plane area can be defined as the moment of inertia of the area about an axis perpendicular to the plane of figure and passing through the C.G. of the area. For circular cross section this point will be center of the circle. Polar moment of shaft of cross section is.

J=π/32 ×D^4