Frequency-dependent viscoelasticity effects on the wave attenuation performance of multi-layered periodic foundations  

作　　者：M.SAFI M.VAKILIFARD M.J.MAHMOODI 

机构地区：[1]Faculty of Civil,Water&Environmental Engineering,Shahid Beheshti University,Tehran 1983969411,Iran [2]Faculty of Mechanical and Energy Engineering,Shahid Beheshti University,Tehran 1983969411,Iran

出　　处：《Applied Mathematics and Mechanics(English Edition)》2024年第3期407-424,共18页应用数学和力学（英文版）

摘　　要：In this paper,layered periodic foundations(LPFs)are numerically examined for their responses to longitudinal and transverse modes in the time and frequency domains.Three different unit-cells,i.e.,2-layer,4-layer,and 6-layer unit-cells,comprising concrete/rubber,concrete/rubber/steel/rubber,and concrete/rubber/steel/rubber/lead/rubber materials,respectively,are taken into account.Also,the viscoelasticity behavior of the rubber is modeled with two factors,i.e.,a frequency-independent(FI)loss factor and a linear frequency-dependent(FD)loss factor.Following the extraction of the complex dispersion curves and the identification of the band gaps(BGs),the simulations of wave transmission in the time and frequency domains are performed using the COMSOL software.Subsequent parametric studies evaluate the effects of the rubber viscoelasticity models on the dispersion curves and the wave transmission for the longitudinal and transverse modes.The results show that considering the rubber viscoelasticity enhances the wave attenuation performance.Moreover,the transverse-mode damping is more sensitive to the viscoelasticity model than its longitudinal counterpart.The 6-layer unit-cell LPF exhibits the lowest BG,ranging from 4.8 Hz to 6.5 Hz.

关 键 词：layered metamaterial periodic foundation complex dispersion curve wave transmission diagram 

分 类 号：P315.9[天文地球—地震学] TU435[天文地球—固体地球物理学]