A mechanical-magneto-thermal model for the tunability of band gaps of epoxy/Terfenol-D phononic crystals

A way based on the temperature effect is investigated to adjust the longitudinal wave band gaps of one-dimensional epoxy/Terfenol-D phononic crystals. For both the cases (with and without consideration of demagnetization effect), the dependences of component materials' effective parameters on temperature are obtained by applying a nonlinear mechanical-magneto-thermal coupling constitutive model and fitting the experimental data, respectively. Further, the influence of temperature on the band structure of wave propagation in phononic crystals consisting of epoxy and Terfenol-D is discussed in detail. Meanwhile, the effects of magnetic field, pre-stress, and filling fraction are studied. Numerical results show that temperature has a significant influence on the band structure of wave propagation in phononic crystals: As temperature rises from −40 °C to 40 °C, the widths of the first, second, and fourth band gaps increase, while that of the third band gap decreases. In addition, the demagnetization effect should not be ignored under a low magnetic field.