Page 236 - Improving Machinery Reliability

Machinery Reliability Audits and Reviews 201

Figure
E., and

n= , 1 \ (3 - 5)

For combined bending and torsion, the factor of safety is obtained from

If bending acts alone, 2, and z,, vanish and the expression for the factor of safety in
the case of unilateral stresses results. When ca and q,, vanish, we have the equation
for n in torsion.

Torsional Stresses Can Be Readily Calculated

For the desired uprate conditions given earlier, we calculate shaft torque output as

The steady torsional stress is, therefore,