d = 10 cm = 0.1 m
T = 8 × 103 Nm
ιmax = ?
Using the relation, Tmax = (σ/16) τmax.D3
τmax = 16T/π.D3
τmax = (16 × 8 × 103)/(π.(0.1)3)
τmax = 40.74 X 106 N/m2
Principal stress = 2. τmax
Principal stress = 2 × 40.74 × 106
Principal stress = 81.48 × 106 N/m2