BACKGROUND

Working on enhancing elastic cloaking, the Fresnel institute - a French state laboratory - developed a structure that can channel transverse elastic waves around a zone, which is to be insulated from a source in plates.

This approach help controlling vibrations, which are detrimental in mechanical applications including aeronautics, car and ship industries.

 KEY BENEFITS vs. STATE OF THE ART

Surface elastic waves can be detrimental in mechanical applications (e.g. plate vibrations in airplanes, boats, cars, helicopters, motorbikes, manufactories, watches). Recent developments for controlling electromagnetic waves can be used for controlling mechanic vibrations structures such as shells and plates.

Figure shows a ring-shaped structure capable of channeling elastic waves in a plate.

The principle consists in modifying the mechanicals properties or density of the material that surrounds the shell or the plate to be protected from vibrations.

For a given wave frequency, simple numerical simulations provide a large class of material solutions that will be used to develop the isolated part.

• Unlike existing anti-vibration systems that act by reducing the amplitude of the waves, our system redirects vibrations around the area to be protected.

• Unlike existing systems that are more or less wave shock absorbers, our system has a life time theoretically unlimited (no wear/fatigue of springs, foam or other).

Development Status

Experimental test on real systems under real conditions of use (wavelength, thickness of plate ranging from a few micrometers to centimeters)

APPLICATIONS

• A mechanical system of which one part must be isolated by the vibrations of the other

• Vibration control, shock absorber systems for aeronautics and car industries

• Wave absorbers for offshore structures and coastal engineering