1) stress induced in a shaft

1)shear stress due to torque, i.e, due to a torsional load.

2) Bending stress due to the forces acting upon machined elements like gears, pulleys etc, as well as due to the weight of the shat itself

3) Stress due to combined torsional bending loads

2) Equivalent torque

$\tau_e = \sqrt{m^2+T^2}$

Equivalent bending moment

$M_c =\frac{1}{2}[M_c + \sqrt{M^2+T^2}] $

Sometimes in the problems, $K_f$ and $K_b$ is given where $K_f$ = shock and fatigue factor for bending $K_b$ = shock and fatigue factor for twisting

Then equivalent torque
$M_c =\frac{1}{2}[(K_b M_c) + \sqrt{(K_bM)^2+(K_bT)^2}] $

Design an overhung shaft to transmit power through a pulley by the means of a belt drive. The pulley is of weight 250N and located at 100mm, Overhanging from the bearing the diameter of the pulley is 200mm and the maximum power transmitted is 10kN at 1400 rpm. the angle of the lap is $180^0$ and the coefficient of friction is 0.3. The combined coefficient shock and fatigue factor for bending hoisting are 2 and 1.5 respectively. select a suitable material for the shaft and design the shaft from maximum shear stress theory. The pulley transmits power to another pulley below it.

The weight of the pulley W = 200N

The diameter of the pulley D = 200mm

P = power = 10KN