Pentamodal property and acoustic band gaps of pentamode metamaterials with different cross-section shapes

摘要: Abstract Pentamodal property and acoustic band gaps of pentamode metamaterials with different cross-section shapes, including regular triangle, square, pentagon, hexagon circle, have been comparatively studied by finite-element method. Results show that for the varying diameters circumcircles in thick thin ends unit ( D d ), ratio bulk modulus to shear B / G ) bandgaps these five structures perform similar changing tendency. With increasing , decreases single-mode bandgap moves toward high-frequency direction decreasing normalized bandwidth Δ ω g ). keeps around respective average value, firstly then low-frequency . Complete appears as reaching critical value each given direction. For same parameters triangle case has highest lower frequency broader bandwidth.