▎ 摘　　要

In this study, a cylindrical microshell stability reinforced by graphene nanoplatelets is investigated while an axial load is applied uniformly. In addition, viscoelastic foundation covers the composite nanostructure. Therefore, the impacts of the small scale parameter are studied while nonlocal strain gradient theory (NSGT) is considered. The present research deals for the first time with the consideration of viscoelastic, strain-stress size-dependent parameters along with taking into account of various boundary conditions (BCs), especially C-F ones put into effect on the proposed theory. The governing equations (G.Eqs) and BCs have been obtained utilizing energy method and solved with assistance of the generalized differential quadrature method (GDQM). Besides, for the validation of the results, the results of the current model are compared to the results acquired from analytical method. The results show that, viscoelastic foundation, patterns of GPL distribution, nonlocal parameter, length scale parameter, layers' numbers, boundary condition as well as GPL weight function have considerable impact on the stability of the GPLRC cylindrical microshell. Another significant result is that; for C-F B.Cs, at the higher value of the parameter, the influence of the on the dimensionless buckling load of the structure is much more remarkable in comparison with the lower one which in results section is investigated in detail. The results of the present investigation would be informative for design and fabrication of the microactuators and microsensors.