Research on Local Buckling of Stainless Steel Lipped C-Section Beam Around Strong-Axis

To study the local buckling capacity of stainless steel beams with lipped C-sections under strong axis bending, tensile tests were performed on 12 stainless steel coupons based on S30408 austenitic stainless steel (AISI304) in flat and corner areas, and mechanical properties and stress–strain curves were obtained. Then, local buckling capacity tests were performed on 6 specimens of stainless steel beams under strong axis bending to determine their mechanical properties and failure mechanism. The failure phenomenon, load–displacement curve, load–strain curve and local buckling capacity were determined. Results show that the failure modes of the specimens are local buckling failure of the flange and web at mid-span. Additionally, a refined finite element analysis model was developed using Python and ABAQUS to simulate and analyse the mechanical performance and local buckling capacity. Then, the analytical results were compared to the test results, and the accuracy of the refined model was verified. Then, the refined model of the stainless steel C-section beam was simplified including the constraint simplification model, which considered different flange constraints and initial imperfections, and the length simplification model, which was based on different length and support constraints. The comparative analysis results showed that the constraint simplification model can simulate the local buckling failure mode more accurately than other models. Additionally, initial imperfections were shown to have little effect on the local buckling capacity; however, specimen length and the bearing constraint condition did affect the local buckling capacity.