Buckling of Coped Steel Beams

Abstract

An approximate energy method for evaluating the buckling capacity of coped beams subjected to concentrated load at the mid‐span has been developed. The method consists of evaluating several trial buckling loads by varying a shape parameter 7. The lowest of the trial loads represents the buckling load. It is shown that the proposed method yields buckling loads which are close to those obtained experimentally. It was found that the reduction in buckling load due to coping can be quite significant depending upon the particular situation. This fact has been ignored by the AISC specification. The standard buckling equations are usually based upon the assumption that the load is acting through the shear center. It was found that the effect of load acting on the top flange (rather than the shear center) is very significant—even for uncoped beams. In coped beams, the effect of mismatched shear centers at the junction of the coped and uncoped part further adds to the same effect. These effects are also ignored by the AISC specification.