Effective velocity of 2D phononic crystals with rectangular lattice.
The effective velocity of elastic waves for two-dimensional (2D) phononic crystals with rectangular lattice in the long-wavelength limit is studied by numerical simulations. It is demonstrated that, for all three propagating modes, not only the modes polarized in-plane (L wave and SV wave), but also the mode polarized out-plane (SH wave), the effective velocities are distinctly anisotropic and the slowness curves exhibit twofold symmetry. The anisotropy increases as the filling fraction increases or as the width to length ratio of the lattice decreases, and high anisotropy can be obtained in phononic crystals with large contrast between material parameters, which is much higher in rectangular lattice than in square lattice with the same material parameters. Owing to these dependences, the effective velocity can be controlled in engineering.
Zhou
Xiao-Wei
XW
Key Laboratory of Modern Acoustics, MOE, and Institute of Acoustics, Nanjing University, Nanjing 210093, China.
Zou
Xin-Ye
XY
Wang
Tie-Hai
TH
Cheng
Jian-Chun
JC
D000162:Acoustics; D016880:Anisotropy; D003198:Computer Simulation; D008420:Manufactured Materials