Flexural-torsional stability of sandwich tapered I-beams with a functionally graded porous core

The present research deals with the flexural-torsional buckling analysis of sandwich web and/or flanges tapered doubly-symmetric I-beam. All section walls are composed of two metal face layers and a functionally graded (FG) porous core. It is assumed that the material properties of the porous core vary gradually in the longitudinal direction according to the simple power-law function considering the even distribution of porosities. Based on Vlasov’s theory for thin-walled cross-section, the governing equations are derived via the energy method. The effect of axial load eccentricity is also considered in the formulation. The differential quadrature method is used to estimate the buckling load. In special cases, the results are compared to other available studies. Then the effects of gradient index, axial load eccentricity, porous coefficient, thickness ratio and tapering parameter on stability behavior of a simply supported three-layered sandwich tapered  I-beam with FG porous core are comprehensively assessed. The numerical outcomes of this paper demonstrated that the normalized flexural-torsional buckling load decreases with an increase in the porosity volume fraction.