幂指数棱台声子晶体对薄板振动弯曲波的调控特性研究

Flexural wave manipulation in thin-slab structure with power exponent prismatic phononic crystals

针对薄板结构的振动控制,提出了一种幂指数棱台声子晶体构型,并对其带隙的产生机理和影响因素进行了分析,结果表明提出的幂指数棱台声子晶体具有三个弯曲波完全带隙,其中第二带隙宽度可达850 Hz。联合数值仿真和试验方法对声子晶体的弯曲波带隙进行了验证。随着棱台结构高度的增加,三个带隙的带宽扩大。棱台的幂函数幂次升高会使带隙的起始频率与终止频率降低,而边缘厚度的增高会弱化能量聚焦效应使带隙的宽度逐渐变窄。具有线缺陷的声子晶体板可使带隙频段内的弯曲波沿着设计路径传播。

The thin-slab structure with a new form of phononic crystals is constructed.The mechanism and influencing factors of band gap are analyzed.The influence of power change on vibration reduction of phononic crystal plate is studied.Three complete phononic band gaps are obtained.The bandwidth of the second band gap reaches 850 Hz.As the height of the prism increases,the bandwidth of the three bandgap begins to widen.The power of the prism increases,the start and end frequencies of the band gap decrease,while the increase of the edge thickness weakens the energy focusing effect and gradually narrows the bandwidth of the band gap.By using the linear defect and band gaps of phononic crystals,the waveguide effect of thin-slab structure with phononic crystals is achieved.The study provides a new concept to manipulate the flexural wave of thin-slab structure.