The Limiting Width-to-Thickness Ratio for Web of H-Columns

A brief introduction on the limiting width-to-thickness ratio of web of GB 50017—2017 is presented for axially loaded H-column, and possible problems are pointed out. The edge yielding criteria is used to approximate the overall instability of the column and to determine the web stresses at this state to compute the local buckling stress of the web and the corresponding normalized width-to-thickness ratio of the web. Based on the effective width formulas of plates in AISI and European codes EC3-1-5, the limiting width-to-thickness ratio of the web at which the full width is effective is obtained. The results revealed that the limiting ratio shall be related to the normalized slenderness of column. Comparison with the current code formula is given. Approximate formulas are proposed. The presented method is more rational because it considers the effect of overall bending on the web stress distribution and local buckling.