Tunability of longitudinal wave band gaps in one dimensional phononic crystal with magnetostrictive material

Ways for controlling and adjusting the longitudinal wave band structures of one dimensional (1-D) rod phononic crystals with magnetostrictive material are theoretically investigated by the plane wave expansion method. Z-L model is adopted to accurately describe the constitutive relations of phononic crystal containing magnetostrictive material. Taking the magneto-mechanical coupling into account, the longitudinal wave band structures are calculated through the development of effective elastic constant, piezomagnetic constant, and magnetic permeability for magnetostrictive rod. Numerical results show that the longitudinal wave band gaps characteristics are significantly influenced by the applied static magnetic field and compressive pre-stress. Some new phenomena, such as the multi-peaks of the band gap widths corresponding to the varying filling fraction of the binary rod phononic crystal, are investigated. (C) 2014 AIP Publishing LLC.