Numerical modeling of lean duplex stainless steel hollow columns of square, L-, T-, and +-shaped cross sections under pure axial compression

In this paper, finite element (FE) studies for LDSS (Lean Duplex Stainless Steel) hollow columns with square, L-, T-, and +-shaped cross sections (i.e., SHC, LHC, THC and +HC respectively) are presented using ABAQUS, to gain an understanding of the cross sectional shape effects. The LDSS hollow columns having equal material cross-sectional areas with thickness varying from 5 m to 20 mm were subjected to uniform axial compression. Short/Stocky columns with lengths (∼1800 mm) of about three times the outer width of square were considered for the analyses. Based on the analyses, it has been found that for all the NRHCs (i.e., LHC, THC and +HC) considered, a nearly linear variation of Pu with section thicknesses has been observed, although the increase for SHC was relatively slower in thinner sections (t<12.5 mm). The % increase in Pu with 300% increase in t (from 5 m to 20 mm) has been found to be ∼1273%, 1252%, 1041% and 679%, respectively, for square, L-, T-, and +-shaped sections. The gain in Pu for LHC, THC and +HC sections as compared (expressed as Pu/Pu(sq)) to SHC are in the range 120%–150%, 130%–170%, 140%–230%, respectively. Ductility at ultimate load has been observed to be ∼0.1–0.6% for SHC, LHC and THC (all thicknesses), and +HC (t≤10 mm).