Design Optimization of Piezocomposites Using a Homogenization Model: From Analytical Model to Experimentation

Area of Science:

• Materials Science
• Electrical Engineering
• Solid Mechanics

Background:

• Activating non-conductive smart-structures often involves piezoelectric patches.
• Ensuring electrical contact requires conductive layers, which can alter piezoelectric properties.

Purpose of the Study:

• To investigate the impact of conductive electrode layer thickness on piezoelectric properties.
• To model and quantify the resulting changes in electromechanical coupling.

Main Methods:

• Derived a model based on Hashimoto and Yamagushi's approach to predict the effect of electrode layers on piezoelectric coefficients.
• Experimentally characterized NAVY II PZT piezoelectric transducers with varying brass electrode thicknesses (50-400 microns) using IEEE standards.

Main Results:

• A decrease in the lateral electromechanical coupling factor (k31) was observed and quantified as electrode thickness increased.
• The derived model showed excellent agreement with experimental data.

Conclusions:

• The thickness of the conductive electrode layer significantly impacts the electromechanical coupling of piezoelectric transducers.
• The developed model accurately predicts these changes, supporting its use in designing embedded actuators and sensors for smart-structures.