On the nonlinear vibration behavior of doubly curved FG-GRMMC shell panels with multilayer corrugated FG-GRMMC core

Abstract

This study presents an analytical investigation into the nonlinear vibration characteristics of doubly curved sandwich panels composed of multilayer corrugated FG-GRMMC cores and two face sheets made from functionally graded graphene-reinforced metal matrix composite (FG-GRMMC). The harmonic excitation and thermal environment are applied for the considered panels. An improved homogenization scheme is developed to represent the effective mechanical behavior of the layered corrugated core, accounting for both geometric configurations and graphene distribution patterns. The governing equations are established within the framework of Donnell shell theory, incorporating von Kármán geometric nonlinearity, and are reduced to a set of nonlinear ordinary differential equations using the Ritz energy approach. Both free and forced vibration responses are examined, including natural frequencies, nonlinear frequency-amplitude relationships, and dynamic responses. The effects of key parameters such as core geometry, graphene gradation, temperature variation, and shell curvature are systematically evaluated. The results demonstrate that the multilayer corrugated core significantly enhances the dynamic stiffness and vibration performance of the structure. The results offer valuable contributions into the design of sandwich shell structures subjected to complex thermomechanical and dynamic loading conditions.