Structural dynamics of 3D printed thermoactive metamaterials for low-frequency band gaps
| Autor: | Bizjan, Gašper |
|---|---|
| Přispěvatelé: | Slavič, Janko |
| Jazyk: | slovinština |
| Rok vydání: | 2023 |
| Předmět: |
3D tiskanje
local resonance Harmonic balance method thermoactive material 3D printing strukturna dinamika vibroizolacija lokalna resonanca kvazi ničelna togost structural dynamics vibration isolation metamaterials udc:531.391:534.83:004.92(043.2) low-frequency band gaps metoda harmonskega ravnotežja metamateriali quasi-zero stiffness termoaktivni material nizkofrekvenčne pasovne vrzeli |
| Popis: | V delu je predstavljena uporaba 3D tiskanega metamateriala za namen nizkofrekvenčne vibroizolacije v strukturni dinamiki. Osnovna reprezentativna celica metamateriala, ki jo tvorita resonator in struktura nelinearne togosti, izkazuje visoko statično in nizko dinamično togost. Tako imenovana kvazi ničelna togost omogoča pojav pasovne vrzeli pri zelo nizkih frekvencah. Preko obravnavane osnovne reprezentativne celice, katere periodična razporeditev tvori metamaterial, določimo lastnosti neskončno dolgega metamateriala z analitično izpeljavo disperzijskih krivulj. Termoaktivne lastnosti uporabljenega prevodnega filamenta omogočajo adaptivno krmiljenje togosti in prilagajanje pasovne vrzeli preko segrevanja z Joulovim tokom. Numerične simulacije prenosnosti končnega števila celic potrjujejo pasovne vrzeli pri enakih frekvencah kot disperzijske krivulje. Končni metamaterial in eksperimentalna prenosnost kažeta obstoj pasovnih vrzeli, ki so zmožne znižati prenosnost tudi za 30 do 40 dB, vendar se te zaradi lezenja materiala nahajajo pri višjih frekvencah, kot napoveduje teorija. This thesis presents the use of 3D printed metamaterials for low-frequency vibration isolation in structural dynamics. The basic representative cell of the metamaterial consists of a resonator and a structure with nonlinear stiffness, exhibiting high static and low dynamic stiffness. The so-called quasi-zero stiffness enables the appearance of band gaps at very low frequencies. Through the considered basic representative cell, whose periodic arrangement forms the metamaterial, the properties of an infinitely long metamaterial are determined by analytically deriving dispersion curves. The thermoactive properties of the used conductive filament allow for adaptive stiffness control and adaptation of the band gap through Joule heating. Numerical simulations of the transmission of a finite chain of cells confirm the existence of band gaps at the same frequencies as the dispersion curves. The final metamaterial and experimental transmission show the existence of band gaps capable of reducing transmission by 30 to 40 dB, but these are located at higher frequencies than predicted by theory due to material creep. |
| Databáze: | OpenAIRE |
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