Experimental investigation of frequency and damping characteristics of magneto-rheological fluid core sandwich beams

Abstract

In dynamic systems mechanical vibration amplitudes may range from a few nanometres to meters. When the vibration amplitudes are high the system may lead to failure or lost it function. Structures often tend to failure because of the high vibration amplitudes. These vibrations can be reduced by changing the stiffness or damping of the structure. One of the approaches is semi-active damping achieved by using Magneto-rheological fluid (MRF) as core material in a sandwiched beam. Magneto-rheological(MR) fluids change from fluid state to quasi-solid state when it is activated by a magnetic field. Adding MR fluids to mechanical systems may significantly improve their dynamic response. This study aims to analyse the free vibration response of the cantilever sandwich beam filled with the MR fluid as core material with Magnetic field intensity. A sandwich cantilever beam with Composite material as face layer and Magneto-rheological fluid as core was fabricated. Free Vibration test is performed on a sandwich beam filled with MR fluid under the external magnetic field generated by permanent magnets. Magnitude of Viscoelastic moduli of the MR fluid increases with magnetic field intensity as the fluid becomes semi-solid. The aim of the work is to analyse the influence of Magneto-rheological effect on the beam response with respect to externally applied magnetic field. Vibrations of the beam are registered with magnetic field and without magnetic field strength. Obtained data is utilized to analyse the dependency of magnetic field strength on the beams natural frequency and damping. © 2020 Author(s).