In this paper, the postbuckling analysis is performed for shear deformable sandwich beams which comprise a functionally graded porous metal foam core bonded by two face layers. The beam model is based on the Timoshenko beam theory and von Karman type nonlinear strain-displacement relationships. The material constants of the porous core vary smoothly and continuously along the thickness direction. Three porosity distributions, i.e., a symmetric non-uniform porosity distribution, an asymmetric non-uniform porosity distribution, and a uniform distribution are considered. The coefficients of porosity and mass density determine the variation amplitudes of material constants and are related by using typical mechanical properties of an open-cell metal foam. The nonlinear governing equation system is derived and then solved with the aid of the Ritz method in conjunction with a direct iterative algorithm. The adopted Ritz trial functions satisfy the employed geometric boundary condition: clamped-clamped. The postbuckling behaviors of the sandwich porous beams are examined by conducting a parametric study. The parameters varied include the porosity distribution, porosity coefficient, slenderness ratio, and thickness ratio. It is found that among the three porosity distributions considered, the sandwich beam with a symmetric non-uniform porosity distribution in the metal foam core has the best postbuckling performance.
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