Analysis Of Vibration Characteristics Of Mrf Sandwich Beam Under Homogeneous And Non-homogeneous Magnetic Field

As a new type of smart materials,magnetorheological fluid has the ability to instantly change the damping and stiffness under the varying magnetic field.And the change process is reversible and controllable.Because of these advantages,it has received widespread attention in the semi-active control of vibration in engineering structures.The MRF can be compounded into elastic materials to form a sandwich structure.The mechanical properties of magnetorheological fluid can be changed by external magnetic field.Then the vibration characteristics of sandwich structure can be controlled.So far,there are many scholars have studied the application of magnetorheological materials in clutch,damper and precision machining equipment,etc.However,there are few researches on the applications of MRF to the vibration control of sandwich plate or sandwich beam.In this study,the vibration characteristics of the MRF sandwich beam were analyzed theoretically and discussed experimentally.The main research works of this article include:1? In this paper,the MRF was considered as the linear viscoelastic materials.Based on the Hamilton principle,the finite element model of sandwich beam was established.According to the theory of laminated structure vibration analysis,each layer of the stiffness matrix and mass matrix were calculated,and then were stacked up.Then the work that the vibration characteristics of the MRF sandwich beam under homogeneous and non-homogeneous magnetic field was done.2? Lab VIEW software was used to design the experimental data acquisition and analysis system,and the vibration test rig of MRF sandwich beam was built.A sandwich beam with a MRF core and an aluminum face sheet was designed.The experiment test rig was set up to investigate the vibration characteristics of the MRF sandwich beam under homogeneous and non-homogeneous magnetic field.The effects of different magnetic fields and the thickness of the magnetorheological fluid layer on the vibration frequency of MRF sandwich beams were analyzed.Numerical analysis and experimental results showed that the vibration frequency of MRF sandwich beam is controllable.The experiment results showed that the frequency of the MRF sandwich beam increased as the uniform magnetic field increased.The frequency of the MRF sandwich beam decreased when the non-homogeneous magnetic field that applied on the beam was moved from the clamped end of the beam to the free end of the beam.The theoretical analysis and experimental results showed the same trend,but there were some differences in the values.