Propagation of nonlinear waves in graded flexible metamaterials

Abstract

Attenuation and amplification of wave amplitudes are the major concerns for the design of engineering structures subjected to dynamic/impact loadings. As a kind of special structures, flexible chains have been demonstrated to support solitary waves when they undergo impacts. Here we propose a method to harness graded flexible structures with stiffness gradient to realize the decrease and increase of the amplitude of the pulse or pulse-like signals, which contributes to the design of absorber and mechanical triode. By combining the positive gradient with the concept of amplitude gap, we find the pulse or pulse-like signals can be distorted and destructed, which paves a new way to implement impact mitigation.