The axle of an automobile is acted upon by the forces and couple shown in Figure 3. Knowing that the diameter of the solid axle is 32 mm, determine (a) the principal planes and principal stresses at point H located on top of the axle, (b) The orientation of the carbon fibre lay direction 350 N m 0.15 m 3 kN 0.2 m 3 kN Figure 3