Use of magnetorheological elastomer in an adaptive sandwich beam with conductive skins. Part II: Dynamic properties

The second part of this research is to present the field-dependant dynamic property of a sandwich beam with conductive skins and a soft core composed of a magnetorheological elastomer (MRE) part and two non-MRE parts. The MRE part of the core is configured to operate in shear mode and hence the dynamic properties of the sandwich beam can be controlled by magnetic fields due to the field-dependant shear modulus of MRE material. According to the analytical solution for the magnetoelastic loads applied to conductive deformable bodies presented in the first part, the model of the proposed sandwich beam is developed via Hamilton principle. A simply supported MRE-based sandwich beam excited by a vertical force distributed uniformly in a narrow region around the center of the beam is simulated. The anti-resonant frequencies and the resonant frequencies are found to change with the applied magnetic field up to 30%. The procedure to seek the optimal length of MRE part is also presented. Although MRE is a soft material with shear modulus about 0.4 Mpa, this research indicates that the sandwich configuration can well utilize the controllable property of MRE to design applicable smart devices with controllable stiffness.