Elastodynamic wave propagation in graded materials: simulations, experiments, phenomena, and applications

Area of Science:

• Solid Mechanics
• Materials Science
• Acoustics

Background:

• Elastodynamic wave propagation is crucial in various engineering fields.
• Understanding wave interaction with material interfaces is essential for designing advanced materials.
• Traditional interfaces lead to predictable wave reflection and transmission.

Purpose of the Study:

• To develop a numerical model for elastodynamic wave propagation in joint half-spaces with graded interfaces.
• To investigate the influence of functionally graded layers on wave behavior.
• To experimentally verify the frequency-dependent wave filtering effects.

Main Methods:

• A two-dimensional numerical simulation model for elastodynamic wave propagation.
• Modeling graded interfaces with smoothly varying elastic properties and densities.
• Experimental verification using a short-pulse-laser-acoustic setup on vapor-deposited films.

Main Results:

• Graded layers introduce frequency and wavelength-dependent refraction and reflection.
• Long wavelengths are predominantly reflected, while short wavelengths are transmitted.
• Experimental results confirm the predicted frequency-dependent filtering behavior.

Conclusions:

• Functionally graded interfaces offer unique control over elastodynamic wave propagation.
• The thickness of the graded transition zone dictates wave behavior, unlike thin interfaces.
• This research provides insights into wave filtering using graded microstructures at terahertz frequencies.