Stress distribution and elastic local buckling strength of tapered H-shaped beam under shear bending

From the economical point of view, tapered H-shaped beams have been designed in steel frame structures. The purpose of this paper is to investigate the elastic local buckling strength of H-shaped beam with web depth tapered under shear bending. Theoretical analysis with energy method is conducted by separating H-shaped beam into two plate elements, web and flange. As prerequisite for the buckling analysis, stress distribution of each plate element is supposed in consideration of geometrical characteristic of tapered form. The validity of the supposed stress distribution is confirmed from the static loading test. From the analysis, the effect of the tapered form to buckling behavior is inspected and the approximation for buckling strength is derived for each plate element. In addition, coupled buckling behavior of two plate elements is also investigated with finite element method.