A high carbon steel shaft is used in an engine and subjected todifferent loads. In order to
analyse the stress in the shaft, consider a rectangular elementwithin the material. This
element is subjected to compressive stress of 135 MPa and shearstress of 166MPa in the
vertical direction. The compressive stress in the horizontaldirection is 176MPa with a shear
stress of 115MPa.
a. Sketch the state of stress on this element.
b. Determine the maximum and minimum normal and shear stresses andtheir plane of
orientation.
c. If the yield strength of the material is 350MPa, Poison’s ratiois 0.32, and factor of
safety is 5, determine the diameter of the shaft to avoidfailure.
d. What will be the difference in the analysis above if there is anadditional torsional
load (T) and bending moment (M).
e. Show how you can use any theory of failure to design thisshaft.
f. What are the challenges of applying the theories of failure inactual engineering
practice and as a design engineer, how would you deal with thesechallenges.
