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

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