Free vibration of bidirectional functionally graded sandwich beams using a first-order shear deformation finite element formulation

In this paper, free vibration of bidirectional functionally graded sandwich (BFGSW) beams is studied by using a finite element formulation. The beams made from three distinct materials are composed of three layers, a homogeneous core and two bidirectional FGM face layers with material properties varying in both the thickness and longitudinal directions by power gradation laws.