BEHAVIOR OF UNSTIFFENED SLENDER WEB OF TAPERED I-SHAPED STEEL MEMBERS

Abstract

To evaluate the tapered-web plates coefficients of elastic buckling, an extensive finite element analysis was conducted. different boundary conditions for the web plate were included along with different geometric parameters. Three loading conditions were considered: uniform compression, pure bending, and pure shear. New formulas are proposed for the axial, bending, and shear buckling coefficients for tapered plates. The existing procedure for the combined compression and bending interaction is validated against the proposed formulas. Moreover, a new expression for the tapered plates slenderness limit is proposed meeting the AISC methodology. The proposed formulas were found to be valid for singly tapered members by introducing newly proposed reduction factors. An experimental program is performed using three specimens that are axially loaded. A three-dimensional numerical finite element model is established considering both material and geometrical nonlinearities. The finite element model successfully simulates the experimental tests. New procedures are proposed to predict the web’s effective width in the same AISC generalized effective width formula. The new procedures are validated against both the experimental results and the finite element models. Another experimental program is performed using three specimens that are selected to fail in shear without any significant flexural deformations. A three-dimensional numerical finite element model is established considering both material and geometrical nonlinearities. The finite element model is successfully calibrated to simulate the experimental tests. New procedures are proposed to predict the ultimate shear strength which is validated against the existing experimental results.