散射型组合周期排桩带隙特性的影响因素研究

Study on influencing factors of band gap characteristics in the scattering type periodic row piles

为明确散射型组合周期排桩带隙的影响因素及作用机制,在通过相似模型试验进行验证分析的基础上,对散射型组合周期排桩带隙产生机理进行分析,并采用有限元方法研究了不同影响因素下的带隙特征。结果表明:带隙范围内的竖向和横向加速度最大衰减程度分别达到95.9%和87.61%,带隙分布特征与数值模拟结果基本一致;散射型组合周期排桩带隙主要受填充率、周期常数、材料密度、基体弹性模量和晶格类型等因素影响;随着填充率减小和周期常数增大,散射型组合周期排桩更易于获得低频带隙,但带宽变窄;通过减小基体密度或增大散射体密度可获得较大带宽的高频带隙;随着基体弹性模量的增大,带隙的边界频率同步向高频迁移;对于圆形散射体,六角晶格构型的带隙性能整体优于正方晶格。研究结果可为散射型周期排桩优化设计及应用提供参考。

To clarify the influencing factors and mechanism of band gaps in the scattering-type periodic row piles,a validation analysis is carried out in this study based on similar model experiments.Subsequently,this study analyzes the band gap formation mechanisms to determine the band gap distribution characteristics of scattered-type combined periodic row piles.The finite element method is employed to investigate the band gap distribution features under various influencing factors.The result shows that the maximum attenuation degree of vertical and lateral acceleration in the band gap range reaches 95.9%and 87.61%.The band gap distribution features are consistent with the numerical simulation results,verifying the correctness of the computational analysis method.The band gap of scattering-type combined periodic pile rows is caused by the multiple scattering of elastic waves between the matrix and the scatterer and the conversion of P-wave and S-wave.The band gap is mainly influenced by factors such as filling ratio,periodic constant,material density,matrix elastic modulus,and lattice type.As the filling ratio decreases and the periodic constant increases,scattering-type periodic row piles are more likely to obtain low-frequency band gaps,but the bandwidth narrows.Reducing the matrix density or increasing the scatterer density can result in wider high-frequency gaps.Additionally,as the matrix elastic modulus increases,the boundary frequency of the gap shifts towards higher frequencies,and the bandwidth increases gradually.The variation in the elastic modulus of scatterers has an insignificant effect on the characteristics of the bandgap.For circular scatterers,the hexagonal lattice configuration demonstrates superior band gap performance and fill utilization ratio compared to the square lattice configuration in the case of the same filling rate.These research findings can provide a reference for the optimization design and application of the scattering-type periodic row piles.