Free vibration and supersonic flutter analysis of a sandwich microbeam with FGP core and CNT-reinforced face sheets on visco-Pasternak foundation

Abstract

ABSTRACT In this study, the vibration and flutter behaviors of a sandwich microbeam with a functionally graded porous (FGP) core and carbon nanotube (CNT)-reinforced face sheets resting on a visco-Pasternak foundation are thoroughly investigated. The different dispersion patterns of CNTs are compared to each other and the properties of the porous cores are derived based on the symmetric porosity distribution patterns. The governing equations are formulated according to the Reddy beam theory (RBT) and Hamilton’s principle. For the numerical solution, the harmonic differential quadrature method (HDQM) is employed, and a comprehensive numerical analysis is carried out within the framework of the modified couple stress theory (MCST). The aerodynamic loading is modeled using the classical piston theory, and aerodynamic damping is neglected due to its relatively minor influence in the supersonic regime considered in this study. Furthermore, the effects of various parameters, such as the CNT volume fraction, CNT agglomeration, and pore distribution pattern, are examined to provide a detailed and accurate insight into the instability behavior of such structures. The obtained results can serve as valuable guidelines for the optimal design of lightweight and high-strength structures in aerospace and advanced engineering applications.