Domain Switching-Based Nonlinear Coupling Response for Giant Magnetostrictive Materials.

Area of Science:

• Materials Science
• Solid Mechanics
• Magnetism

Background:

• Nonlinear magnetostrictive behavior in materials like Terfenol-D is complex.
• Understanding multi-field coupled phenomena (magnetic, elastic, thermal) is crucial for material applications.
• Existing models may not fully capture microstructural interactions and hysteresis.

Purpose of the Study:

• To develop a multilevel, three-dimensional constitutive model for predicting Terfenol-D's nonlinear magnetostrictive response.
• To incorporate interactions between magnetic domains, grains, and polycrystalline complexes.
• To account for coupled magnetic, elastic, thermal, and mechanical phenomena.

Main Methods:

• A microscopically phenomenological approach utilizing domain rotation mechanism.
• A fully coupled self-consistent homogenization scheme.
• Application of Boltzmann functions and an adapted Jiles-Atherton model for hysteresis.
• Taylor series expansion of the Gibbs function.

Main Results:

• The model successfully predicts the nonlinear magnetostrictive response of Terfenol-D under various external loads and magnetic excitations.
• It accurately captures the influence of different thermal environments.
• Grain-scale bulk strains are calculated using Boltzmann functions and homogenization.

Conclusions:

• The developed model provides a robust framework for understanding and predicting complex magnetostrictive behaviors.
• It offers theoretical guidance for the precise control of nonlinear vibrations.
• The model aids in the optimal design of rotating giant magnetostrictive transducers at multiple scales.