In this thesis, the in-plane dynamic response of curved sandwich beams with functionally graded graphene platelet reinforced composite (FG-GPLRC) face sheets and porous core are investigated. The governing equations are derived based on the higher order shear deformation theory (HSDT) using Hamilton’s principle. Then, in order to discretize the governing equations, the finite element method for the spatial domain and Newmark’s method in time domain were used. The effective elastic properties of face sheets are obtained using Halpin-Tsai micromechanical model and the other material properties are also obtained using the rule of mixture. Mechanical properties of the closed-cell cellular solids under Gaussian Random Field scheme are applied to characterize the variation of material properties of porous core. In order to validate the presented formulation, the results obtained in this research have been compared with the results in the available references. After checking the accuracy of the results, the effects of beam opening angle, the mass fraction of graphene platelet (GPL), the number of GPL reinforced layers in the face sheets, the porosity coefficient in the core, different aspect ratio, different distribution patterns of GPLs and also the effect of boundary condition on the natural frequency and dynamic response of the system has been investigated. In the following, the effect of moving load speed on the dynamic response of the system under different conditions has been investigated. The numerical results showed that the different types of GPLs distribution and porosity affect the stiffness and the dynamic behavior of the beam. It was also found that the mass fraction of GPLs has a significant effect on the natural frequency and dynamic behavior of the structure.