In this paper, the band structure analysis of the thermoelastic wave propagation in a phononic crystal (PC), which it is reinforced by graphene platelets (GPLs) and carbon nanotubes (CNTs), is presented. The reinforced PC beam is made of periodic unit-cells including a metal section and a GPLs/CNTs-reinforced epoxy section. The Green-Naghdi theory of the generalized coupled thermoelasticity with energy dissipation and a new modified micromechanical model to predict the mechanical properties of the reinforced section are employed in the analysis. An analytical solution and the transfer matrix method are adopted to compute the band structures. The frequency band-gaps are obtained and the effects of the GPLs and CNTs volume fractions on the width and location of the band-gaps are analyzed and discussed in details. The results show that the GPLs influence the frequency band-gaps and the band structures of the thermoelastic wave propagation in the reinforced PC beam much more remarkably than the CNTs. The proposed analytical solution method, the modified micromechanical model and the presented results can be employed for designing the reinforced PC structures by the GPLs, CNTs or both of them and also for tuning the band-gaps in the future researches.

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