Love waves in functionally graded piezoelectric materials by stiffness matrix method

Area of Science:

• Materials Science
• Acoustics
• Solid Mechanics

Background:

• Ultrasonic guided waves are crucial for non-destructive testing and device applications.
• Functionally graded piezoelectric materials (FGPMs) offer tunable electromechanical properties.
• Analytical methods for FGPMs can be complex and limited in scope.

Purpose of the Study:

• To develop and validate a numerical matrix method for analyzing ultrasonic guided wave propagation in FGPM heterostructures.
• To compare the numerical approach with existing analytical methods.
• To investigate the influence of material gradients on wave behavior and device performance.

Main Methods:

• A numerical matrix method based on the stiffness matrix approach was employed.
• The FGPM layer was stratified into homogeneous layers to apply the ordinary differential equation method.
• Love wave propagation was analyzed for electrical open and short circuit conditions.

Main Results:

• The numerical method showed good agreement with analytical solutions, demonstrating its validity.
• Different gradient variations in mechanical and electrical properties led to opposing effects on wave propagation.
• The study determined dispersive curves and phase velocities, analyzing the impact of gradient coefficients on electromechanical coupling, stress, electrical potential, and mechanical displacement.

Conclusions:

• The stiffness matrix method provides a flexible and conceptually simple approach for analyzing ultrasonic guided waves in FGPMs.
• The findings are valuable for designing high-performance acoustic surface devices and accurately predicting Love wave propagation.
• Understanding gradient effects is key to optimizing FGPM-based acoustic applications.