In this work. an anharmonic mass-in-mass system that can be employed as a nonlinear seismic metamaterial is represented as an equivalent anharmonic mass-spring system via an effective medium approach. The dispersion relation and the behavior of the effective mass as a function of the angular frequency obtained in the regime of weak anharmonicity deviate from those of the corresponding... https://www.ealisboa.com/mega-sale-Sol-Sunguard-Altitude-Sunscreen-1-5oz-big-savings/