Time-domain investigation of an external cloak for antiplane elastic waves

Space folding techniques based on non-monotonic transforms lead to a new class of 2D isotropic cloaks with constant negative shear modulus and spatially varying density for antiplane elastic waves. We consider an external cloak consisting core positive density, shell simultaneously density. Such core–shell resonant system creates virtual folded region outside the shell. To handle such physical parameters in time-domain, two-step strategy is used: (i) assuming (Drude Lorentz-types) effective frequency-domain; (ii) returning time-domain by applying formalism auxiliary fields. numerically show that, at designed central frequency, scattering cylindrical wave incident upon finite set small clamped obstacles drastically reduced after lapse time, when they are placed close neighborhood cloak. However, cloaking efficiency decreases source intense near field moreover short times, breaks down.