PROPAGATION OF ACOUSTIC WAVE IN ONE-DIMENSIONAL PHONONIC CRYSTALS WITH MAGNETORHEOLOGICAL FLUIDS

In this paper we present a kind of phononic crystals(PCs) with magnetorheological fluids(MRFs) and its band gaps can be tuned by the magnetic field for the reason that modulus of MRFs can be changed by means of the magnetic field. Finite element method and experimental method are applied to study the propagation of acoustic waves in the PC. Firstly, we obtain the variety of the shear storage modulus and the loss modulus of MRFs under different magnetic flux density. Secondly, relationships between the magnetic flux density and band gaps of the PC are achieved. We find that band gaps change in response to the magnetic field at first, but they keep constant when MRFs reach magnetic saturation state. The results demonstrate the feasibility of tuning band gaps by MRFs with changed magnetic field.