Surface wave propagation control with locally resonant metasurfaces using topology-optimized resonatorsa)

Area of Science:

• Solid Mechanics
• Materials Science
• Acoustics

Background:

• Locally resonant elastodynamic metasurfaces are key for suppressing surface waves, particularly in low-frequency applications like seismic barriers.
• Current design methods rely on extensive dispersion analyses to tailor resonator geometry for specific frequency bandgaps.
• Topology optimization offers a systematic approach to designing these metasurfaces.

Purpose of the Study:

• To present a systematic design methodology for locally resonant elastodynamic metasurfaces using topology optimization.
• To achieve desired frequency bandgaps by matching multiple antiresonances with target frequencies.
• To validate the methodology through numerical and experimental investigations.

Main Methods:

• Employing topology optimization to design individual local resonators.
• Matching multiple antiresonances with target frequencies to create bandgaps.
• Analyzing resonator response to in-plane and out-of-plane excitations mimicking surface wave motion.

Main Results:

• Topology optimization successfully conceives locally resonant metasurfaces with frequency bandgaps.
• Combining longitudinal-like and flexural-like antiresonances creates wider, combined bandgaps.
• Numerical simulations show good agreement with experimental validation.

Conclusions:

• The proposed topology optimization method is effective for designing locally resonant metasurfaces.
• Matching multiple antiresonances provides a powerful tool for controlling bandgap characteristics.
• This approach enables the creation of wider bandgaps for enhanced surface wave suppression.