QUESTION 14 A steel pipe having a yield stress σY= 270 MPa, is to carry an axial compressive load P = 1200 kN, A factor of safety of 1.8 against yielding is to be used. If the thickness (t) of the pipe is to be one-eighth of its outer diameter. The minimum required outer diameter (dmin.) in (mm.)is: 153 192 124 151