Wave propagation in highly anisotropic polycrystals: A numerical perspective from an unstructured-mesh-based...

Area of Science:

• Materials Science
• Computational Mechanics
• Non-Destructive Testing

Background:

• Ultrasonic non-destructive testing (NDT) is crucial for characterizing polycrystalline materials.
• Accurate modeling of ultrasound propagation in highly anisotropic polycrystals with complex grain boundaries remains challenging.
• Existing numerical methods often require dense meshes or lack mature analytical formulations for strong wave scattering.

Purpose of the Study:

• To develop and validate a novel high-order unstructured mesh method for accurate ultrasonic wave propagation simulation.
• To address limitations in modeling wave scattering in anisotropic polycrystals.
• To improve the computational efficiency and accuracy of NDT simulations.

Main Methods:

• Constructed polycrystalline geometry using Voronoi-based tessellation.
• Employed an explicit dynamics solution with high-order mass-lumped unstructured elements with internal nodes.
• Compared simulation results against structured meshes and modified analytical models.

Main Results:

• The proposed high-order mass-lumped unstructured elements accurately represent complex grain boundary geometry.
• Significant enhancements in computational efficiency and accuracy were observed compared to traditional methods.
• Simulated ultrasonic attenuation and phase velocity showed good agreement with analytical and structured mesh results.

Conclusions:

• The developed high-order mass-lumped unstructured mesh method effectively simulates ultrasonic wave propagation in anisotropic polycrystals.
• This method offers a more accurate and efficient approach for NDT applications.
• The findings confirm the method's effectiveness for characterizing grain features in complex materials.