In this paper, buckling analyses of functionally graded porous nanocompo-site cylindrical shells reinforced with graphene platelets (FGPNCS-R-GPLs)under uniform external lateral pressure are performed for the first time.FGPNCS-R-GPLs are built by infiltrating GPLs into the metal matrix contain-ing open-cell internal pores. Hence, different GPLs and porosity distributionpatterns called uniform and non-uniform are considered through the thick-ness of the shell. The modified Halpin-Tsai micromechanics model and therule of mixtures are employed to estimate the effective modulus of elasti-city and to compute density and Poisson’s ratio of the porous nanocompo-site shell respectively. The theoretical governing formulations are derivedbased the first-order shear deformation theory (FSDT), and then they aresolved using Rayleigh-Ritz method to obtain the critical buckling pressure.Present formulations are validated by comparing the present numericalresults with results obtained by finite element methods. Moreover, theeffects of the number layer in the thickness direction, GPLs and porositydistribution patterns, porosity coefficient, GPL weight fraction, GPL shape,circumferential wave number, boundary condition and cylindrical shelldimensions are comprehensively investigated in detail to find the bestparameter values to achieve the maximum buckling resistance of FGPNCS
