An Active and Structural Strain Model for Magnetostrictive Transducers

We consider the modeling of strains generated by magnetostrictive materials in response to applied magnetic elds. The active or external component of the strain is due to the rotation of magnetic moments within the material to align with the applied eld. This is characterized through consideration of the Jiles-Atherton mean eld theory for ferromagnetic hysteresis in combination with a quadratic moment rotation model for magnetostriction. The second component of the strain re ects the passive or internal dynamics of the rod as it vibrates. This is modeled through force balancing which yields a wave equation with magnetostrictive inputs. The validity of a combined transducer model is illustrated through comparison with experimental data.