MATLAB script and COMSOL models of the article "An efficient multiscale method for subwavelength transient analysis of acoustic metamaterials"

A reduced-order homogenisation framework is proposed in the article "An efficient multiscale method for subwavelength transient analysis of acoustic metamaterials", providing a macro-scale enriched continuum model for locally resonant acoustic metamaterials operating in the subwavelength regime, for both time and frequency domain analyses. The homogenised continuum has a non-standard constitutive model, capturing a metamaterial behaviour such as negative effective bulk modulus, negative effective density, and Willis coupling. A suitable reduced space is constructed based on the unit cell response in a steady state regime and the local resonance regime.

• The effective continuum material properties are computed via the MATLAB script provided here.

-A frequency domain numerical example demonstrates the efficiency and suitability of the proposed framework. The macro-scale model is implemented via a COMSOL model provided here.

-The direct numerical simulations (COMSOL models) are also provided here.