A model-based approach for B/A estimation using the finite amplitude insertion-substitution method

Area of Science:

• Acoustics
• Nonlinear Acoustics
• Materials Characterization

Background:

• Accurate estimation of the acoustic nonlinearity parameter (B/A) is crucial for material science.
• Conventional finite amplitude insertion-substitution (FAIS) methods have limitations due to assumptions like plane wave propagation.

Purpose of the Study:

• To develop an enhanced, model-based framework for B/A estimation using the FAIS method in transmission mode.
• To improve the accuracy and robustness of B/A measurements by addressing limitations of existing techniques.

Main Methods:

• Developed a framework that eliminates the plane wave assumption, incorporating shape functions for transducer diffraction and wave superposition.
• Included a correction term for second-harmonic attenuation to handle various attenuation exponents.
• Supported both iterative and direct B/A estimation methods.

Main Results:

• The enhanced framework significantly improves accuracy and robustness in B/A estimation compared to conventional FAIS methods.
• Reduced sensitivity to experimental setup and transducer geometry.
• Validated through simulations and experimental measurements.

Conclusions:

• The proposed framework offers a more precise and reliable method for characterizing the acoustic nonlinearity parameter B/A.
• Provides practical guidance for optimizing experimental parameters for B/A measurements.