EXAMPLE 1.1 AXIAL PRINCIPAL STRESSES A cylindrical specimen of rock, 50 mm in diameter and 100 mm long is subjected to an axial compressive force of kN Find: the normal stress σnθ and shear stress τθ on a plane inclined at 30° to the radial direction; the maximum value of shear stress; the inclination of planes on which the shear stress τθ is equal to one-half τθmax Biaxial stress Bai tap