Question

3) The solid shaft is made of material that has an allowable shear stress of Tallow 12 MPa. Determine the required diameter of the shaft to the nearest millimeter. Please draw a plot of the internal Torque along the length of the shaft. 15 N·m 25 N·m 30 N·m 60 N'm 70 N·m

Answer 1

Given that the allowable shear stress tau _area = tau _allow = 12 mpa from Torque equation T/J = G theta/l = tau /r r = radial distance = d/2 T/J = tau/r tau _max = T/J r = T/ z_p J = polar section modulus = J/r = pi/32 d^4/(d/2) = pi d^3/16 \r\n tau _allow = T/z_p tau proportionalto T tau _max is possible only with the portion DE with torque 70N/m 12 times 10^6 = 70/ pi/16 d^3 d^3 = 16 times 70/12 times pi times 10^6 d = 0.03097m d = 0.03097 times 10^3 mm d = 30.97 mm