Nonlinear wave localization in an acoustic metamaterial with attached masses through one element of main chain

The nonlinear strain solitary waves in a metamaterial mass-in-mass lattice model with a di-atomic symmetry is studied when attached masses tare located through one element of main chain are studied in the continuum limit. The reasonable variables are introduced to account for strains. An asymptotic procedure is developed to reduce coupled continuum equations to a single equation for longitudinal strains. A correspondence with the classic model with a di-atomic symmetry is established. An improvement of the model is suggested to account for a switch-on/off of the parts of the metamaterial model arising due to the studied kind of symmetry. It allows us to change the behavior of the localized nonlinear strain waves. This improvement is important for description of a durability of the metamaterial. Also it helps to understand new heat processes, like thermal diode, in complex symmetric lattices.