Nonlinear Elastic Stability of Web Panels in Built-Up Members

The stability characteristics of web panels in two built-up members, i.e. box-sections and I-sections, are investigated here using a higher order plate bending element. At the beginning, the critical buckling loads of rectangular flat panels under various theoretical states-of-stress (pure shear, in-plane bending, shear and in-plane bending and combined stresses) and boundary conditions (simply supported and restrained by flange panels) are investigated. Then, the buckling behavior of an isolated flat panel is correlated with the stability characteristics of the web panels of built-up members under various loading conditions. The results on the stability behavior of the web panels are presented in nondimensional form for easy reference to designers and researchers.