Wave propagation control in periodic track structure through local resonance mechanism

Abstract

Excessive vibration and noise radiation of the track structure can be caused by the operation of high speed trains. Though the track structure is characterized by obvious periodic properties and band gaps, the bandwidth is narrow and the elastic wave attenuation capability within the band gap is weak. In order to effectively control the vibration and noise of track structure, the local resonance mechanism is introduced to broaden the band gap and realize wave propagation control. The locally resonant units are attached periodically on the rail, forming a new locally resonant phononic crystal structure. Then the tuning of the elastic wave band gaps of track structure is discussed, and the formation mechanism of the band gap is explicated. The research results show that a new wide and adjustable locally resonant band gap is formed after the resonant units are introduced. The phenomenon of coupling and transition can be observed between the new locally resonant band gap and the original band gap of the periodic track structure with the band gap width reaching the maximum at the coupling position. The broader band gap can be applied for vibration and noise reduction in high speed railway track structure.

摘要

高速列车运营过程中轨道结构能够产生剧烈的振动并向外界辐射噪声。虽然轨道结构呈明显周 期特征并具有带隙特性,但其带隙范围小,带隙内弹性波衰减能力弱。为了有效抑制轨道结构振动噪 声,引入局域共振机理拓宽轨道结构的带隙范围,实现轨道结构中弹性波控制。在钢轨上周期性附加 局域共振单元,构成新的局域共振型声子晶体结构,然后分析局域共振单元对弹性波带隙的调控规律, 并阐明带隙的形成机理。研究结果表明,引入局域共振单元后,轨道结构产生新的局域共振带隙,该 带隙较宽且频率范围可调;局域共振带隙与周期性轨道结构原有带隙产生耦合和转化,并在带隙耦合 条件下实现带隙宽度最大化,拓宽后的带隙可用于高速铁路轨道结构振动噪声控制。