A numerical non-linear finite element model has been developed in this research to investigate the resistance of non-prismatic simply supported I-section beams. The sections are assumed to be tapered from both sides with linear variable web widths and constant thickness. The studied beams are subjected to linear moment gradient about the major axis of the sections where bending moments are applied to the wider section of the beam. The model is generated using isoparametric shell elements that accounts for both geometric and material nonlinear nature of the problem. The boundary conditions considered allow the beam to rotate about the major and minor axis and the flanges are free to warp. Sections studied are of slender type that suffers local buckling in their elements. The behavior of these sections is governed by the slenderness of the plate elements comprising the section as well as the overall member slenderness ratios. Therefore, the parameters varied in the analysis cover the above mentioned factors. The geometric imperfections have been included in the analysis by modeling the members curved about their minor axis in a half sin wave. The ultimate moments have been compared with that of the prismatic beams subjected to uniform moment to find out the effect of moment gradient and tapering on the flexural strength.
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