Local Buckling of W Shape Columns and Beams

An analytical method, previously developed and programmed for computer use, is used to carry out an extensive study of the various parameters affecting the local buckling behavior of W shape columns and beams. The effects of flange and web interaction, residual stresses, plate geometry, and inelastic action are included in the study. Specific parameters investigated include web slenderness, flange slenderness, yield stress, residual stress, strain‐hardening modulus, and member length. Local buckling curves of critical loads versus web slenderness are presented for various values of flange slenderness for beams and columns. The results of the study indicate that the present values of flange slenderness $=100$ (260) and web slenderness $=225$ (670), as presently specified for columns in the Canadian Standard, CAN3‐S16.1‐M78, are inappropriate. Values of flange slenderness $=72$ (189) and web slenderness $=300$ (788) are indicated. The results also show that the presently specified values of flange slenderness $=100$ (260) and web slenderness $=690$ (1,810) for Class 3 (non‐compact) sections may be too liberal with respect to the flanges and conservative with respect to the web. Values of flange slenderness $=72$ (189) and web slenderness $=800$ (2,100) are indicated by the study. The effects of all the parameters investigated during the study are shown in the form of local buckling curves as described here.