Poly　(methyl　methacrylate)　(PMMA)/carbon　nanotube　(CNT)　composite　plates　have　been　extensively　used　in　aviation　and　aerospace　fields.　During　intended　service　life,　the　PMMA/CNT　composite　structure　is　prone　to　severe　vibration,　which　leads　to　the　formation　of　cracks　and　the　fracture　of　structures.　In　order　to　achieve　vibration　attenuation,　it　requires　a　fundamental　understanding　of　the　vibration　behavior　of　composite　structures.　Here,　a　molecular　dynamics　(MD)　based　multiscale　approach　is　developed　to　analyze　the　nonlinear　vibration　behavior　of　PMMA/CNT　composite　plate.　Molecular　simulations　are　performed　to　capture　the　mechanical　properties　of　the　composite　and　constituents,　including　longitudinal,　transverse,　and　shear　moduli　of　single-walled　CNT　(SWCNT)　segment,　PMMA　matrix,　and　PMMA/SWCNT　nanocomposite.　The　MD　simulation　results　are　substituted　into　the　extended　rule　of　mixtures　to　derive　the　related　efficiency　parameters,　which　are　used　as　the　fundamental　inputs　in　a　meshless　approach　to　predict　the　nonlinear　vibration　of　macroscale　functionally　graded　(FG)-based　composite　plates.　According　to　the　macroscale　simulation,　it　is　found　that　the　arrangement　of　CNTs　has　a　significant　influence　on　the　nonlinear　vibration　of　FG-based　composite　plates.　The　developed　multiscale　approach　provides　an　efficient　paradigm　of　investigating　the　macroscopic　behavior　of　composite　structure　in　consideration　of　the　mechanical　response　from　microscopic　constituents.　(c)　2020　Elsevier　Ltd.　All　rights　reserved.