Question

A hollow circular shaft has an outer diameter of 100 mm , inner diameter of 50mm and a wall thickness of 25 mm. The allowable shear stress in the shaft is 125 MPa. The maximum torque the shaft can transmit is

• A. 46 kN m
• B. 24.5 kN m
• C. 23 kN m
• D. 11.5 kN m

Answer 1

The correct option is C 23 kN m


Outer diameter = 100 mm
Inner diamteter = 50mm
Radius, r = 50 mm
Wall thickness, t = 25 mm
Allowable shear stress,
$\tau =125$MPa
$\frac{T}{J}=\frac{\tau }{r_0}$
$T=\frac{\tau J}{r_0}$
$=\frac{125\pi ({100}^4-{50}^4)}{32\times 50}$
$=23.0097\times {10}^6$Nmm
$=23$kNm