Elastic Buckling of Thin-Walled Structural Components with Edge-Stiffened Holes

This manuscript explores and quantifies the global, distortional, and local buckling properties of thin-walled structural components with edge-stiffened circular holes. Shell finite element eigenbuckling analysis and recently introduced finite strip and hand approximations are employed to calculate the critical elastic buckling loads of lipped C-section columns and beams. The global buckling approximate method employs classical stability expressions with weighted average section properties derived from a Rayleigh-Ritz energy solution. Stiffened holes are observed to decrease the flexural buckling and flexural-torsional buckling of columns and lateral-torsional buckling of beams, and the edge stiffener only minimally increases the global buckling load when compared to equivalent members with unstiffened holes. Distortional buckling is studied with finite element plate studies and full finite element models of lipped C-section columns. A stiffened hole is observed to increase transverse bending stiffness of the C-section web which in turn increases the distortional buckling load. Local buckling at a hole is studied with full finite element models of thin-walled columns. The edge stiffeners prevent local buckling at a hole, and instead focus buckled half-waves in the gross cross-section between holes with minimal influence on the critical elastic local buckling load.