Lateral Buckling of Doubly Symmetric Beams Containing Openings

When a slender beam is transversely loaded in the plane of its greatest flexural rigidity, it may buckle laterally at a critical load. It is common practice to provide web openings in beams for the passage of service ducts and pipings, for inspection purposes in beam structures, and for other reasons. The presence of web openings not only reduces the ultimate strength of beams, but also the lateral‐buckling capacity. This paper presents a numerical method, based on the energy approach, to predict the critical lateral‐buckling loads of slender, doubly symmetric beams containing unreinforced web openings. The beams are either cantilevered or simply supported and contain openings along their centerlines. The critical loads evaluated numerically are compared with the values obtained experimentally. The study shows good agreement between the numerial and experimental values.