(a)

(b)

(c)

Figure 6: (a) Geometry with associated mesh for the 2D periodic cell representative of the 12.7 mm thick HPPE plate (dimensions in mm). (b) Phase-velocity dispersion curve in the (0 ÷ 500) kHz frequency range with primary and secondary modes for nonlinear analysis highlighted (white circles). (c) Attenuation curve (expressed in dB/m) in the (0 ÷ 500) kHz frequency range with primary and secondary modes for nonlinear analysis highlighted (white circles).