The present paper investigates the implementation of the energy localization phenomenon for enhancing the output harvesting performance. Also in this paper, a linear electromagnetic vibration energy harvester with weakly magnetic coupling is proposed. The designed device is 2 degree-of-freedom (dof) oscillators, which functionalizes the energy localization phenomenon via a springmagnet array. The proposed concept is made up of moving magnets held by elastic springs and coupled by a repulsive magnetic force with a very low mechanical damping. The energy localization is achieved by mistuning the mass of one of the moving magnets. The experimental and theoretical results showing the benefits of the energy localization phenomenon are reported. The maximal average power density harvested by functionalizing the energy localization is P avg = 0.8 µW.cm −3 .g −2 .Hz −2 for a magnetic coupling β = 0.015 .

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This paper investigates the use of a wave-based method in the framework of structural optimisation of composite panels involving advanced components. The wave/finite element method (WFEM) is used to evaluate the influence of a core's geometry on the transition frequency of a sandwich panel involving composite skins. This transition occurs is a sandwich panel when the transverse shear stiffness has a significant influence on the flexural motion, compared to the bending stiffness. It follows that the modal density and the acoustic radiation will considerably increase above this frequency. The periodic waveguide is modelled at the mesoscopic scale using a 3D finite element model of the unit-cell. Therefore this method does not require an homogenisation of the core based on Gibson and Ashby formulations to provide the wave dispersion characteristics. Although the cellular cores compared in this study share the same mass-to-stiffness ratio, a significant alteration of the transition frequency and modal density can be observed compared to honeycomb cores. A periodic octagonal core is designed, providing up to 70 % increase of the transition frequency and a significant reduction of the modal density.