A torsion bar is used as a suspension element for a vehicle. The bar has a diameter of 20 mm. It is subjected to a torsional moment of 450 N # m and an axial tensile force of 36.0 kN. Draw a stress element on the surface of the bar, and then draw the complete Mohr’s circle for the element, find the principal stresses, the maximum shear stress, and also the principal and shear plane angles. What are the minimum yield strength and ultimate tensile strength are required to satisfy following failure theories.
(Assume that design factor, F= 2).
1. Maximum Normal Stress Theory,
2. Maximum Shear Theory
3. Distortion Energy Theory