Question

For a round shaft subjected to pure torsion, the shear stress at the centre (axis) will be

• A. maximum
• B. minimum
• C. zero
• D. the information provided is insufficient

Answer 1

Answer:

C. zero

For a round shaft under pure torsion, the shear stress is maximum at the outer surface and directly proportional to the distance from the center. At the center, the radius is zero, so the shear stress is zero. The torsion equation for a circular member is $\frac {\tau}{r} =\frac{T}{j} = \frac {C\theta}{I}$