Dynamic stability analysis in sandwich composite laminated face structure with partially treated magnetorheological fluid-filled core

Abstract

Sandwich composites with controllable cores have wide applications in aerospace structures. This paper presents a dynamic modeling and stability analysis of sandwich beams with a partially filled magneto-rheological (MR) fluid core covered by laminated composite face sheets in the supersonic flow regime. The equations of motion of the resulting system are formulated using energy expressions and the Hamilton principle. Finite element modeling is employed to solve the equations with different boundary conditions. Initially, free vibration analysis is performed and the effect of the magnetic field on the natural frequencies of the beam is reported. In order to minimize the weight, the magnetorheological fluid is filled at selected cells in the core layer. The locations and sizes of these cells affect the modal characteristics and flutter stability of the beam. Also, the impact of core layer thickness under different boundary conditions is studied. Furthermore, the influence of magnetic field on the critical pressure in supersonic flow regime is investigated using first-order piston theory to identify the unstable regions. The results revealed that the size and position of the MR section in the beam and the applied magnetic field strength drastically influence the natural frequencies of partially treated magnetorheological laminated sandwich beams. The influencing variables are identified from main-effect plots using analysis of variance study.