Optical evaluation of the wave filtering properties of graded undulated lattices

TL;DR

This paper experimentally demonstrates that graded undulated lattices can effectively filter elastic waves over broad frequency ranges due to spatially modulated curvature, leading to broadband wave attenuation.

Contribution

It introduces a novel experimental approach to analyze wave filtering in graded undulated lattices and highlights the role of curvature grading in creating broadband bandgaps.

Findings

Broadband wave attenuation achieved through curvature grading

Experimental validation using laser vibrometry and digital image correlation

Formation of frequency bandgaps in graded lattices

Abstract

We investigate and experimentally demonstrate the elastic wave filtering properties of graded undulated lattices. Square reticulates composed of curved beams are characterized by graded mechanical properties which result from the spatial modulation of the curvature parameter. Among such properties, the progressive formation of frequency bandgaps leads to strong wave attenuation over a broad frequency range. The experimental investigation of wave transmission, and the detection of full wavefields effectively illustrate this behavior. Transmission measurements are conducted using a scanning Laser vibrometer, while a dedicated digital image correlation procedure is implemented to capture in-plane wave motion at selected frequencies. The presented results illustrate the broadband attenuation characteristics resulting from spatial grading of the lattice curvature, whose in-depth investigation is enabled by the presented experimental procedures.