Enhanced wave absorption due to local flexibility on wide beams using mass-spring-damper scatterersa)

Area of Science:

• Acoustics
• Mechanical Engineering
• Materials Science

Background:

• Total absorption of flexural waves in beams is achievable with monopole-dipole scatterers.
• This study explores an alternative configuration using a pair of identical monopole scatterers.

Purpose of the Study:

• To investigate near-total absorption of flexural waves in a thin and wide beam.
• To analyze the resonant modes and their degeneracy for enhanced wave absorption.

Main Methods:

• Theoretical analysis and numerical simulations were employed.
• Experimental validation was conducted to corroborate simulation findings.

Main Results:

• A pair of identical monopole scatterers exhibited resonant modes with monopole and dipole properties.
• Mode degeneracy, achieved by selecting appropriate beam width, led to near-total absorption exceeding 99% in simulations.
• Experimental results confirmed approximately 90% absorption.

Conclusions:

• The interaction with a higher-order localized flexural mode causes the degeneracy of monopole and dipole modes.
• This configuration offers an effective method for achieving high levels of flexural wave absorption in beams.
• The findings are relevant for applications requiring precise control of wave propagation.