局域共振超材料表面波屏障带隙特性与隔振性能
Band gap characteristics and vibration isolation performance of locally resonant metamaterial surface wave barrier
厉超 1庄培芝 2李利平 3张思峰 1周冲1
作者信息
- 1. 山东建筑大学交通工程学院,山东济南 250101
- 2. 山东大学齐鲁交通学院,山东济南 250002
- 3. 山东大学齐鲁交通学院,山东济南 250002;山东大学岩土与结构工程研究中心,山东济南 250061
- 折叠
摘要
为有效解决轨道交通运营引发的地面振动问题,基于声学超材料概念提出一种局域共振超材料表面波屏障(locally resonant metamaterial surface wave barrier,简称LRMB)隔振方法,并采用混凝土和橡胶垫层构造出屏障结构.根据半无限空间弹性动力学理论,推导LRMB带隙计算的解析式,分析橡胶垫、混凝土参数对LRMB带隙特性的影响规律.基于轨道交通地面振动实测数据,探讨LRMB的隔振效果.研究结果表明:LRMB表面波带隙产生主要与其竖向振动有关,基于该模式建立的带隙计算方法是准确的;LRMB橡胶垫厚度增大,带隙起始频率降低,带隙宽度增大;LRMB橡胶垫宽度增大,带隙起始频率升高,带隙宽度减小:LRMB混凝土质量增大,带隙起始频率降低,带隙宽度增大:LRMB原胞数量增多,隔振效率提升,隔振效率达到20～25 dB;以济南轨道交通1号线工程为例,采用LRMB后地面振动衰减可达70％～80％,验证了 LRMB的良好隔振性能.
Abstract
To effectively address the issue of ground vibration induced by the rail transit,a locally resonant metamaterial surface wave barrier(LRMB)vibration isolation method was developed based on the concept of acoustic metamaterials,and the structure model was constructed using concrete and rubber pad.According to the theory of elastic dynamics in semi-infinite space,an analytical calculation formula for LRMB bandgap was derived,and the influences of rubber pad and concrete on LRMB bandgap characteristics was analyzed.The vibration isolation performance of LRMB was further analyzed based on the measured ground vibration induced by the rail transit.The results show that the generation of LRMB surface band gap is mainly related to its vertical vibration,and the band gap calculation method for LRMB assuming vertical vibration mode is accurate.Increasing the thickness of the rubber pads decreases the starting frequency of the bandgap and increases its width.Conversely,increasing the width of the rubber pads increases the starting frequency of the bandgap and decreases its width.Additionally,increasing the mass of the concrete decreases the starting frequency of the LRMB bandgap and increases its width.The vibration isolation efficiency can be improved by increasing the number of primitive cells and the vibration isolation coefficient with 4-6 cells reach 20-25 dB.Using Jinan Rail Transit Line 1 project as an example,the ground vibration attenuation can reach 70％-80％after using LRMB,validating its strong vibration isolation performance.
关键词
声学超材料/表面波/波屏障/带隙特性/隔振性能Key words
acoustic metamaterial/surface wave/wave barrier/band gap characteristics/vibration isolation performance引用本文复制引用
基金项目
山东省自然科学基金(ZR2022QE082)
出版年
2024
国家科技期刊平台
NSTL
万方数据