Consider a W18x35 section made of A992 steel that is used as a compression member. It is simply supported and laterally braced at the ends with warping unrestrained. For this condition, all unbraced lengths are assumed to be equal (Lcx = Lcy = Lcz). 
a. For pure compression loading, use the 2022 AISC Specification to calculate and plot the nominal compression strength curves (Pn vs. Lc) for four different buckling modes: strong-axis flexural buckling, weak-axis flexural buckling, torsional buckling and constrained-axis torsional buckling. For CATB, assume that the constraining axis is located at the intersection of the centerlines of the web and one of the flanges. Plot for Lc ≤ 50 ft. 
b. Briefly discuss the relative strengths of these global buckling modes and any implications that you see for design of steel compression members.