# Non-symmetric flexural wave scattering and one-way extreme absorption

## TL;DR

This paper demonstrates that by configuring pairs of damped oscillators attached to a beam, one can achieve highly asymmetric flexural wave absorption and reflection, including near-total absorption from one side and reflection from the other.

## Contribution

It introduces a method to achieve one-way extreme absorption of flexural waves using impedance-tuned scatterers, a novel approach in wave control.

## Key findings

- Almost total absorption for incidence from one side.
- Near-zero reflection for incidence from the opposite side.
- Distinct wave dynamics compared to acoustic waves.

## Abstract

The possibility of asymmetric absorption and reflection for flexural waves is demonstrated though analytical and numerical examples. We focus on the 1D case of flexural motion of a beam and consider combinations of point scatterers which together provide asymmetric scattering. The scatterers are attached damped oscillators characterized by effective impedances, analogous to effective configurations in 1D acoustic waveguides. By selecting the impedances of a pair of closely spaced scatterers we show that it is possible to obtain almost total absorption for incidence on one side, with almost total reflection if incident from the other side. The one-way absorption is illustrated through numerous examples of impedance pairs that satisfy the necessary conditions for zero reflectivity for incidence from one direction. Examples of almost total and zero reflection for different incidences are examined in detail, showing the distinct wave dynamics of flexural waves as compared with acoustics.