新型半埋入式地震超材料超低频带隙机理及性能研究

(1.西安建筑科技大学 机电工程学院,陕西 西安 710055; 2.西安建筑科技大学 力学技术研究院,陕西 西安 710055; 3.西安建筑科技大学 土木工程学院,陕西 西安 710055)

振动控制; 超材料; 带隙特性; 局域共振

Study on mechanism and performance of ultra-low frequency band gap of new semi-embedded seismic metamaterials
LI Lixia1,2, LI Pengguo1, JIA Qi1, LI Ling1, ZHANG Xicheng3

(1.School of Mechanical and Electrical Engineering,Xi'an Univ. of Arch. & Tech. Xi'an 710055,China; 2.Institute of Mechanics Technology, Xi'an Univ. of Arch. & Tech., Xi'an 710055,China; 3.Shool of Civil engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055,China)

vibration control; metamaterial; band gap characteristics; local resonance

DOI: 10.15986/j.1006-7930.2023.01.013

备注

针对破坏力极强的地震表面波中瑞利波的振动控制,提出一种新型半埋入式地震超材料屏障.相比于传统的地震超材料屏障,这种新型半埋入式超材料屏障将单胞的内外柱体分别单独半埋入土壤中,结构稳定性强且具有低频宽带隙特性.采用有限元法计算了新型半埋入方式下地震超材料屏障的带隙特性,并结合其振型分析了带隙的形成机理,当内外柱体分别单独半埋入时,振子和振动模态各不相同,打开了不同的低频带隙.进一步分析了埋入深度、连接体杨氏模量的变化对带隙机理的影响,其中,埋入深度是影响带隙的主要因素,随着埋入深度的增加,屏障稳定性增强,系统的主导刚度会发生改变,引起了局域共振模态的转变,从而拓宽带隙的宽度.最后,对有限周期模型屏障的振动传输特性进行了计算,并通过EI-Centro地震波对屏障进行了时程分析,加速度幅值衰减超过70%.结果表明:新型半埋入式地震超材料屏障对20 Hz以下的瑞利波具有良好的衰减作用,为地震超材料在减震隔震方面提供新的设计思路和方法.
A new type of semi-buried seismic metamaterial barrier is proposed for vibration control of Rayleigh waves in seismic surface waves with strong destructive force. Compared with the traditional seismic metamaterial barrier, this new semi-embedded metamaterial barrier semi-embedded the inner and outer columns of the unit cell into the soil separately, which has strong structural stability and low-frequency broadband gap characteristics. The finite element method is used to calculate the band gap characteristics of the seismic metamaterial barrier under the new semi-buried mode, and the formation mechanism of the band gap is analyzed combined with its vibration mode. When the internal and external columns are semi-buried separately, the oscillator and the vibration mode are different, and the low frequency band gap is opened. The influence of the embedded depth and Young's modulus of the connector on the band gap mechanism is further analyzed. The embedded depth is the main factor affecting the band gap. With the increase of the embedded depth, the stability of the barrier is enhanced, and the dominant stiffness of the system will change, resulting in the change of the local resonance mode, thus broadening the width of the band gap. Finally, the vibration transmission characteristics of the finite periodic model barrier are calculated, and the time history analysis of the barrier is carried out by EI-Centro seismic wave. The acceleration amplitude attenuation is more than 70%. The results show that the new semi-buried seismic metamaterial barrier has a good attenuation effect on Rayleigh wave below 20 Hz, which provides a new design idea and method for seismic metamaterials in damping and isolation.
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