As the displacement field shows, the energy of the excitation was trapped and then dissipated in metamaterial area.
At first I thought this dissipation mechanism was Bragg Scattering, but then I realize this may not be right. Does anyone figure out what this dissipation mechanism might be?
Measure point is on the right. The top and bottom (in the outer frame area) are set as infinite elements, allowing energy to be transmitted to far field, so that the metamaterial area will not be interfered by reflected energy waves.
The confused point is that, the response at measure point indicates that the energy is reduced by 90%, but I could not tell what kind of energy dissipation mechanism it is from displacement field.