Experimental Demonstration of Elastic-Plastic Wave Propagation in a Discrete Metamaterial

Abstract

We fabricate a discrete phononic crystal with hysteretic force–deflection behavior analogous to elastic–plastic material response, and then measure its response to harmonic excitation. Slider (or Jenkins) elements are introduced to mimic plastic deformation and a ten-cell phononic crystal is constructed from modular unit cells. Modular construction enables calibration and validation of individual components prior to full integration, which is particularly important for the sliding elements. Subsequent frequency-sweep experiments at both elastic and plastic excitation amplitudes demonstrate pronounced wave attenuation aligned with bandgap frequencies arising from Bragg scattering. The presence of this strong attenuation, even at plastic amplitudes, reveals experimentally that bandgaps can continue to block frequencies into the strongly nonlinear, plastic regime. The fabricated system is expected to facilitate future experimental studies of large-amplitude, elastic–plastic wave propagation.