This article presents the structural behavior (load and deformation capacities) of fixed ended Lean Duplex Stainless Steel (LDSS) and Austenitic Stainless Steel (ASS) stub columns of square, flat oval and circular cross sections under pure axial compression, using the commercial finite element analysis (FE) software, Abaqus (2009). To assess the structural responses, parametric studies have been conducted by analyzing 30 stub models, keeping the same perimeter, for tube thicknesses ranging from 3-25 mm. It is found that P_u (Ultimate load) increases with increase in thickness in a nearly linear fashion, with higher increase rate for LDSS as compared to ASS steel. The gain in P_u for LDSS in relation to
P_u(g)( = (P_u(LDSS)- P_u(ASS))/P_u(ASS)×100), increases from ~ 25% to ~ 50% for thinner sections as thickness changes from T = 3 to 15 mm and then stabilized at ~ 50% for T ≥ 15 mm. The deformation capacity (δ_u/Hx100) of square, flat oval and circle increased with increase in thickness and showed almost same value for both steel.

Keywords: Lean duplex stainless steel, Austenitic stainless steel, Axial compression, Square, Circle, Flat oval.