Experimental and numerical assessment of stainless steel equal-leg angles under eccentric compression

This study investigates short-to-intermediate hot-rolled austenitic stainless steel equal-leg angles subjected to combined axial compression and minor-axis bending. Based on the preliminary elastic buckling analysis, an experimental programme was conducted on compact equal-leg angle specimens (L63.5×4.76 and L = 275 mm) tested under four different eccentricities ( e = 0-30 mm) with cylindrically pinned supports allowing rotation about the minor axis. The experimental investigation comprises (i) material characterisation, (ii) geometric measurements and initial imperfection assessment using 3D optical scanning, and (iii) four beam-column tests instrumented to capture equilibrium paths, cross-section torsional rotation and minor-axis flexural displacements. A solid finite element model was developed in ANSYS and validated against the experimental results to perform a parametric investigation covering equal-leg angle sections with width-to-thickness ratios ( b / t ) ranging from 10 to 18.67 and member non-dimensional flexural-torsional slenderness ( λ FT ) values ranging from 0.64 to 1.62, establishing the axial force and minor-axis bending interaction behaviour ( N – M v ). The numerical results are then used to assess the design provisions of Eurocode 3: Part 1-4, which lead to overly conservative resistance predictions and do not fully capture the governing global flexural-torsional instability mechanism. Consequently, two additional investigations are assessed while maintaining the European design methodology.