Nonlinear vibrations of all-composite sandwich plates with a hexagon honeycomb core: Theoretical and experimental investigations

•Amplitude-dependent vibrations of all-composite honeycomb sandwich plates are investigated.•The modified equivalent elastic moduli of hexagon honeycomb core are assumed.•A model considering the material nonlinearity of hexagon honeycomb core is developed.•Effect of key parameters of the core on nonlinear vibration behaviors are evaluated.