Fig. 4: Local resonance bandgap control in an aligned MRE-based metamaterial.
From: Local resonance bandgap control in a particle-aligned magnetorheological metamaterial
a Metamaterial components, sensor locations, and geometric parameters. b Out-of-plane displacement field at 200 Hz in the absence of a magnetic field (Sim 1) and at a magnetic field strengths of 1600 Oe (Sim 2). c Experimental apparatus. Out-of-plane measurements at the locations of P1 and P2 are used to generate a transmission transfer function over the desired frequency range. d Transmission spectrum from simulations (line) and experiments (scattered points) corresponding to magnetic field strength of (from top to bottom) 0, 850, 1300, and 1600 Oe. Shaded area denotes bandgap region in each case as predicted from Bloch-wave analysis. e Unit cell dispersion diagram in the absence of magnetic field (reference case). Shaded area denotes the field-free bandgap region. Side insets depict examples of out-of-plane and in-plane deformations. f Magnetic field variation mechanism via adjustable gaps between facing permanent magnets. The shown distances correspond to the transmission plots in the adjacent rows of (d). g Percentage normalized change in the starting γS and ending γE bandgap frequencies as a function of the applied magnetic field, corresponding to the different rows of (d) and (f).
