A Constitutive Model for Ferromagnetic Alloys: A Fully Coupled Analysis

  • 詹 侑書

Student thesis: Doctoral Thesis


Magneto-mechanical coupling behavior plays an important role in active devices and thermal effects from surrounding environments has significant influence on the responses of ferromagnetic alloys In order to design the smart devices containing the ferromagnetic constitutes it is necessary to have a reliable constitutive law to accurately describe the multi-physics coupling behavior for the ferromagnetic alloys This study presents a three-dimensional nonlinear constitutive model for predicting magnetostriction and magnetization of giant ferromagnetic alloys subject to magnetic intensity as well as undergo the mechanical loadings The thermo-magneto-mechanical coupling constitutive law is derived based on a phenomenological approach within continuum mechanics A Gibb’s free energy function is firstly formed and then it is followed by its Taylor series expansion in order to obtain characteristic material parameters for the ferromagnetic alloys The experimental data obtained from available literatures on the hysteretic behavior operating under both magnetic fields and prestressed conditions are used to evaluate the accuracy of the proposed constitutive model Results show that the model can adequately predict the nonlinear strain responses and magnetization in wide regime Parametric studies are also conducted to examine the effect of loading rates temperature and coupled magneto-mechanical stimuli on the overall performance of the ferromagnetic alloys
Date of Award2019
Original languageEnglish
SupervisorChien-hong Lin (Supervisor)

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