Objective of this paper is to present a predictive design of a mechanical filter which is capable of filtering frequencies along a waveguide. A mathematical design procedure is described to filter Lamb wave frequencies in a confined space. Complementary to the existing idea of wave guiding in a plate within an absolute band gap created by a 2D array of phononic crystals, the proposed acoustic metamaterial has a capability of wave guiding using a single but continuous array of crystals in a confined space. Further through fabrication, experiments and numerical modeling, sequential filtration of a frequency band is demonstrated. A conceptual design of a selective pass band filter (i.e., a mechanical pass band filter) is achieved by enhancing the phenomenon of steering, guiding and confinement of the Lamb waves inside a proposed waveguide, fabricated by spirally arranging a number of cylindrical quartz crystals, bonded on an aluminum plate. Experimentally Lamb waves were excited by a PZT transducer inside the spiral waveguide using a wideband chirp signal and the out-of-plane wave motion was recorded using a one dimensional scanning laser Doppler vibrometer (SLDV). The propagation within the waveguide was evaluated in time, frequency and wave number domains. By analyzing the equifrequency contours and the transmission spectra inside the waveguide, the study demonstrate that the frequency based Lamb wave sensing and spectral separation of different frequencies are mechanically enhanced. Frequency based sensing capabilities of the waveguide depends on the geometrical location of the wave front inside the waveguide, which is a function of spatially varying radius and phase rotation due to the spiral geometry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.