Local Buckling in Continuous Composite Beams

Continuous composite beams can only be designed by simple plastic theory if the hinges at the supports have adequate rotation capacity. This is often controlled by local buckling of the webs and flanges. Tests to determine the effect of local buckling on the rotation capacity of composite beams under negative bending are described, Comparisons are made with limiting web and flange slenderness ratios currently used in steel design both in Great Britain and in North America. It is found that some of the existing regulations can be applied to composite beams, but that others may be unsafe, for both steel and composite beams. Alternative rules are proposed.

J. Jay Climenhaga and R. Paul Johnson