A bar of 20 mm in diameter and 300 mm in length is subjected to an axial compressive stress of 20 MPa.
(a) If the material undergoes brittle failure under a tensile stress of 80 MPa, what twisting moment would just produce brittle failure while the compressive force acted?
(b) If the material yields plastically at a yield strength of 80 MPa, what twisting moment would just produce yielding while the compressive force acted?
