One of the innovative ideas behind lightweight design and vibration control of structures is to incorporate into the structures means of passively reducing the propagation of elastic waves, or the unwanted vibrations – that means that vibrations and noise can no longer propagate freely in the structures in addition to be highly damped or attenuated. This can be achieved by designing adequate conditions to control (elastic) waves – such as periodic variation of mechanical properties or local resonances which results in frequencies range where wave propagation is highly damped. The development of such new ‘materials’ is part of a research partnership with Le Mans university – the goal of the joint program is to apply this outstanding technology into the industrial world. Big names from the aerospace, automotive, railway and energy sectors have already shown their interest.
These newly developed ‘engineered materials’ such as periodic structures will certainly be part of tomorrow lightweight structures such as satellites and automotive parts. However lightweight and robust design still requires the savor-faire of structural dynamics and vibro-acoustic, core competencies of METRAVIB. One cannot dismiss the importance of dynamical characterization of structures, estimation of operational dynamical forces and damping, key parameters used in designing with the aid of numerical methods (such finite elements) : this industry-proven approach combining numerical design and experimental qualification has been used and perfected by METRAVIB engineers for decades.
METRAVIB and Le Mans University joined together via their joint research laboratory FullFields to work on:
- Non-resonant meta-materials to create band-gap in vibration over a large structure like a wind turbine.
- Resonant meta-materials for low-frequencies phenomena as in an electrical transformer, generators and motors.
- Acoustic Black Holes for damping improvement in mid and high frequencies like in an electric car structure.