Abstract: The reduction of low-frequency vibration and noise has been a challenging task. A design of phononic crystal plate with periodic novel spiral resonators is introduced based on the locally resonant mechanism of phononic crystals. The low-frequency band gap characteristics of the proposed structure are investigated numerically and experimentally. It is found that the interaction between the local resonances and the traveling wave modes in the plate results in the formation of the locally resonant band gap, whose bandwidth depends on interaction strength and can be modulated by changing structure parameters. By combining the numerically calculations and experimental measurements, the proposed phononic crystal structure is demonstrated to possess a broadband gap in low-frequency range below 250 Hz. The lowest frequency of the band gap is 42 Hz. There is a high level of agreement between the finite element calculation results and the experimental results. The structure design and its results provide theoretical basis and an effective way for phononic crystal to obtain band gaps in low-frequency range, which provides potential applications prospect in the low-frequency noise and vibration reduction.

Key words: Local resonance, Low-frequency band gap, Phononic crystal, Vibration control