Vibration Control of Functionally Graded Panels using Parallel Resonators

Abstract

Functionally graded materials (FGM) are often an integral part these days in many engineering applications, such as, nuclear structural components, spacecraft and marine structures, thermal barrier coatings used for military applications, etc. These structures are also susceptible to dynamic loads varying from harmonic to impulse type of loadings which are in the form of rotating engines, sudden blasts and others. These loadings often pose serious threats to the structural systems by inflicting fatigue damages or by driving the system in tune with its resonating frequency that eventually lead to the complete collapse of the structure. Therefore, a vibration control strategy needs to be devised to protect these structures from unwanted vibrations due to the external loading. A passive vibration control strategy is proposed in the present research work to control the vibration response of a flat panel made of functionally graded material. At first, the FG plate is numerically modelled using the finite element (FE) method to calculate its response due to a point harmonic force. Ceramic (Alumina) is used for the top part of the FG plate while the bottom is made of metal (Aluminium) and the material property is smoothly varied from ceramic to metal using the power law distribution. Then, several resonators consisting of spring-mass system and parallel to each other are attached to both sides of the panel to isolate the response in the resonating frequency ranges. The FE model for the FG plate with resonator is developed and the controlled vibration response is obtained. The controlled response indicates that the resonators are efficient to produce band-gaps in the resonating frequency regime compared to the bare FG plate.