针对汽车板件结构低频振动和噪声的控制问题，提出一种新型C形槽声子晶体结构。采用有限元法计算结构的能带曲线并结合运动模态对其带隙进行分析，利用位移传输特性验证结构的减振能力，引用等效模型阐明结构的物理参数对带隙的影响。结果表明，C形槽声子晶体带隙的产生主要依靠局域共振模态下共振单元对基体板振动的抑制作用。调整结构的物理参数相当于改变系统的等效质量或等效刚度，进而影响带隙的范围。合理的参数可使结构以5mm的厚度在200Hz左右的范围形成完全带隙，并在更低的频率范围形成弯曲波带隙。此外，对应带隙范围的振动衰减最高为69dB，表明C形槽声子晶体板具有良好的减振效果。研究为声子晶体获得低频带隙提供了理论依据，在汽车低频减振降噪方面具有一定应用前景。

In order to control the low-frequency vibration and noise in vehicle plate structure, a new C-slot phononic crystal structure is proposed. The finite element method is used to calculate the band curve of the structure and to analyze the band gap combined with the motion mode. The displacement transmission characteristics are used to verify the vibration reduction ability of the structure. The effect of physical parameters on the band gap is illustrated by the equivalent model. The results show that the band gap of the C-slot phononic crystal mainly depends on the suppression of the matrix plate by the resonant unit in the local resonance mode. Adjusting the physical parameters of the structure is equivalent to changing the equivalent mass or equivalent stiffness of the system, which affects the range of the band gap range. Reasonable parameters can make the structure form a complete band gap in the range of 200Hz with 5mm, and form a curved band gap in the lower frequency range. In addition, the vibration attenuation in the corresponding band gap range is 69dB, which indicates that the C-slot phononic crystal plate has a good vibration reduction effect. The research provides a theoretical basis for obtaining low-frequency band gap of phononic crystals, and has a certain application prospect in the field of low-frequency vibration and noise reduction in vehicle.