Pulse Dynamics of Flexural Waves in Transformed Plates. (11th February 2021)

• Record Type: Journal Article
• Authors: Tang, Kun; Xu, Chenni; Guenneau, Sébastien; Sebbah, Patrick
• Is Part Of: Advanced functional materials. Volume 31:Number 15(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-02-11
• Subjects: cloaking -- homogenization -- mechanical metamaterials -- mirage effect -- pulse dynamics -- transformation elastodynamics -- waveguide modes; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202009266
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Coordinate‐transformation‐inspired optical devices have been mostly examined in the continuous‐wave regime: the performance of an invisibility cloak, which has been demonstrated for monochromatic excitation, is likely to deteriorate for short pulses. Here, pulse dynamics of flexural waves propagating in transformed plates is investigated. A practical realization of a waveshifter and a rotator for flexural waves based on the coordinate transformation method is proposed. Time‐resolved measurements reveal how the waveshifter deviates a short pulse from its initial trajectory, with no reflection at the bend and no spatial and temporal distortion of the pulse. Extending the strategy to cylindrical coordinates, a wave rotator is designed. It is demonstrated experimentally how a pulsed plane wave is twisted inside the rotator, while its wavefront is recovered behind the rotator and the pulse shape is preserved, with no extra time delay. The realization of the dynamical mirage effect is proposed, where an obstacle appears oriented in a deceptive direction. Abstract : The pulse dynamics of flexural waves propagating inside a 3D‐printed transformed plate is investigated. Time‐resolved measurements reveal how a pulsed plane wave is twisted inside the rotator, while its wavefront is recovered behind the rotator and the pulse shape is preserved, with no extra time delay.