Inelastic Buckling in Steel

Plastic design methods assume that local buckling of flanges and webs of WF-beams will not occur during the formation of plastic hinges. Such severe conditions made the re-examination of the problem of plate buckling in the inelastic range necessary. In contradiction to accepted opinions, it was found that steel columns and plates can be compressed beyond the yield point and even into the strain hardening range without buckling. Theoretical results for the required geometric proportions are presented and comparison is made to experimental results obtained from tests on model columns, angles, and WF-beams. Furthermore, consideration is given to the problem of buckling between the elastic limit and the yield stress.