Elastic Stability of Continuous Beams

Although the flexural-torsional buckling of simply supported I-beams has been investigated extensively, both theoretically and experimentally, comparatively few studies have been made of continuous beams. The theoretical work on this subject is summarized, and a series of experimental studies of small scale continuous I-beams described. This includes 86 buckling tests on four two-span beams and three symmetrical three-span beams, and a number of subsidiary tests. The model beams were of aluminum, and two different cross sections were tested. The experimental results are compared with the theoretical predictions of the elastic critical loads and good agreement is demonstrated for most cases. These experimental results support a simple approximate analysis of the elastic interaction buckling of continuous beams in which three significant combinations of critical loads are used to predict the full range of critical load combinations.