Elastic Wave Nonreciprocal Transmission Equipment Based On Weakly Nonlinear Phononic Crystals

The paper studies an elastic wave one-way transmission equipment based on weakly nonlinear phononic crystals. It has realized the elastic wave propagate forward, while reversed the wave is inhibited from propagating. The dispersion of weakly nonlinear periodic structure is amplitude-dependent. The model combines asymmetric structures to realize different amplitudes while the wave arrives at the periodic structure. The goal is one-way transmission of elastic wave.In this work, an acoustic diode (AD) model that relatively has a high forward-power-transmission rate and preserves the frequencies of acoustic waves is proposed. Theoretical analysis presents that the proposed AD is highly similar to electrical diodes, having characteristics like forward, reverse, and breakdown. The forward pass rate reaches 50%, while the forward pass rate little. The significant rectifying effect of the proposed AD is verified numerically.Besides, wave propagation in two-dimensional periodic lattices is investigated, especially wave dispersion, such as dependent bandgaps and wave directivity. The predictions are verified by numerically integrating the equations of motion. An elastic wave one-way transmission equipment based on two-dimensional weakly nonlinear periodic structure is proposed. Both ends of this model are around with damping absorbing boundary layer. Asymmetric structures including triangle and rectangle are used to realize different amplitudes while the wave arrives at the phononic crystals. One-way transmission of elastic wave is realized.