Stochastic analysis of locally resonant linear and hysteretic metamaterials for seismic isolation of process equipment

作     者：Bursi, Oreste S. Basone, Francesco Wenzel, Moritz 

作者机构：Univ Trento Dept Civil Environm & Mech Engn Via Mesiano 77 I-38123 Trento Italy Univ Enna Kore Engn & Architecture Fac Viale Olimpiadi I-94100 Enna Italy 

出 版 物：《JOURNAL OF SOUND AND VIBRATION》 (声音与振动杂志)

年 卷 期：2021年第510卷

页      面：116263-116263页

核心收录：

学科分类：07[理学] 082403[工学-水声工程] 08[工学] 070206[理学-声学] 0802[工学-机械工程] 0824[工学-船舶与海洋工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：European Union Italian Ministry of Education, University and Research (MIUR) [L 232/2016] 

主　　题：Phononic periodic structures Finite locally resonant metafoundations Ultralow-frequency domain Nonlinear programming Equivalent linearization technique 

摘      要：Periodic metafoundations have proven to inherit valuable properties from wave propagating in phononic periodic structures in the very low-frequency regime. Therefore, finite locally resonant metafoundations (LRMs) represent a novel type of seismic isolation for ultralow-frequency applications. In this context, it is still unknown the impact that massive resonators with varying frequencies or devices with hysteretic behavior can entail on the whole system performance. For this purpose, we develop and optimize two finite locally resonant multiple degrees of freedom (MDoF) metafoundations in this paper: i) a foundation endowed with resonators, linear springs and linear viscous dampers tuned to multiple frequencies;and ii) a foundation equipped with fully nonlinear hysteretic dampers. Both are optimized considering the stochastic nature of ground motion, modelled with a modified Kanai-Tajimi filter in the stationary frequency domain, and a massive MDoF superstructure, chosen to be a fuel storage tank. In order to take all of the above-mentioned effects into account, we establish a procedure based on nonlinear programming that is able to optimize any number of parameters. More precisely, to optimize the nonlinear behavior of damper devices we employ a Bouc-Wen hysteretic model. Therefore, we reduce the nonlinear differential equations of Bouc-Wen models to a system of linear equations through the stochastic (equivalent) linearization technique. Moreover, we test the optimized systems against natural seismic records both with linear and nonlinear time history analyses. To investigate the role of hysteresis on the nonlinear band structure, we derive linearized and nonlinear dispersion relationships for the uncoupled periodic metafoundation. Finally, we obtain further detailed information on the nonlinear wave propagation by means of a spectro-spatial analysis.