Angle of twist for stepped shafts

[manian]

can somebody help me with the design procedure for calculating the angle of twist in a stepped shaft ?

 

[lyletk]

Manian,

The process is fairly simple and straight forward. The total angle of twist of a shaft is obtained by adding algebraically the angles of twist of each component part.

PHI = SUMMATION(TL/GJ)

PHI = ANGLE OF TWIST (in radians)
T = TORQUE
L = LENGTH OF SHAFT
G = MODULUS OF RIGIDITY
J = POLOR MOMENT OF INERTIA (pi*r^4 /2 for round shaft)