Experimental Evaluation of the Force Transmissibility of Phononic-Inspired Vibration Isolators
This article is devoted to the experimental evaluation of force transmissibility observed at Phononic-inspired Vibration Isolators (PIVIs) built of two-materials (alternately steel and cork agglomerate) and their combination in series with helical coil springs (HS). The fact that traditional vibration isolators may present a satisfactory performance in a narrow frequency range motivates the development of the PIVI as an alternative solution. Indeed, the PIVI can be designed to present significant wider frequency gaps, designated as Attenuation Regions (ARs), between two consecutive axial natural frequencies. Hence, in this study, three different devices are experimentally evaluated in terms of force transmissibility: the HS, the PIVI and the combined structure (CS) composed of a PIVI in series with a HS. The results clearly demonstrate the capability of the CS in attenuating the force transmissibility, where the PIVI contributes with its AR, thus operating as a “filter” in a specific frequency range, while the HSs add flexibility to the CSs, which may be advantageous for impact loads and/or transient-case scenarios. The authors believe that the capability, relevance and impact of the PIVIs have high potential for noise and vibration reduction applications, in a wide-range of engineering applications.
KeywordsTransmissibility Vibration isolation Phononics Cork agglomerate Experimental Passive devices
The authors would like to acknowledge: the Fundação para a Ciência e a Tecnologia (FCT) for the financial support of a working member of this work through the Instituto de Plasmas and Fusão Nuclear (IPFN), a research institute of Instituto Superior Técnico (IST) and through the PhD grant SFRH/BD/61186/2009; and Instituto de Engenharia Mecânica (IDMEC), a research unit of IST, for additional financial support.
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