Smart Metamaterials and Metastructures -- Using internal resonances to improve structural vibration control

Abstract

Metamaterials and metastructures have several applications such as vibration, acoustic and vibroacoustic attenuation, acoustic absorption and insulation, vibration and shock mitigation, wave propagation control and focusing, among others. They are inspired on phononic crystals that exhibit bandgaps, that are frequency ranges where elastic or acoustic waves cannot propagate. However, bandgaps in metamaterials depend on the properties of the local resonances, that act as vibration absorbers, and not on the size of the periodic cell. This concept motivated the search for designed structures with locally resonant metamaterial-based finite structures, so-called metastructures, that could exhibit low-frequency bandgaps with relatively small structures. Numerous research groups have explored the feasibility of vibration absorbers in low-weight flexible structures, including the use of distributed low-size mechanical and electromechanical vibration absorbers. The latter was possible thanks to the development of synthetic piezoelectric materials, that are smart materials that couple mechanical stresses and strains with electrical charges and potentials. There is growing interest in the use of internal resonances to improve structural vibration control, while there is still room for substantial improvement in existing techniques and solutions. In particular, the combination of mechanical and electromechanical sub-systems, acting either complementary or simultaneously, seems to point to potentially well performing solutions. The main objective of this research proposal is to study the modeling, analysis, design and optimization of structures with mechanical and electromechanical internal resonances to improve structural vibration control.