A Multiphysics Thermoelastoviscoplastic Damage Internal State Variable Constitutive Model including Magnetism

Technical Report · 17 May 2024

DOI:https://doi.org/10.2172/2377306· OSTI ID:2377306

Malki, Mounia ^[1]; Hostemeyer, M. F. ^[2]; Cho, H. E. ^[2]; Peterson, Luke A. ^[3]; Dickel, Doyl E. ^[3]; Capolungo, Laurent ^[4]; Baskes, Michael I. ^[5]

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1. International Univ. of Rabat, Rabat (Morocco)
2. Liberty Univ., Lynchburg, VA (United States)
3. Mississippi State Univ., Starkville, MS (United States)
4. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
5. Univ. of North Texas, Denton, TX (United States)

We present a macroscale constitutive model that couples magnetism with thermal, elastic, plastic, and damage effects in an Internal State Variable (ISV) theory. Previous constitutive models did not include an interdependence between the internal magnetic (magnetostriction and magnetic flux) and mechanical fields. Although constitutive models explaining the mechanisms behind mechanical deformations caused by magnetization changes have been presented in the literature, they mainly focus on nanoscale structure–property relations. A fully coupled multiphysics macroscale ISV model presented herein admits lower length scale information from the nanoscale and microscale descriptions of the multiphysics behavior, thus capturing the effects of magnetic field forces with isotropic and anisotropic magnetization terms and moments under thermomechanical deformations. For the first time, this ISV modeling framework internally coheres to the kinematic, thermodynamic, and kinetic relationships of deformation using the evolving ISV histories. For the kinematics, a multiplicative decomposition of deformation gradient is employed including a magnetization term; hence, the Jacobian represents the conservation of mass and conservation of momentum including magnetism. The first and second laws of thermodynamics are used to constrain the appropriate constitutive relations through the Clausius–Duhem inequality. The kinetic framework employs a stress–strain relationship with a flow rule that couples the thermal, mechanical, and magnetic terms. Experimental data from the literature for three different materials (iron, nickel, and cobalt) are used to compare with the model’s results showing good correlations.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: 89233218CNA000001
• OSTI ID: 2377306
• Report Number(s): LA-UR--24-25590
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ferromagnet
magnetism
magneto-mechanical effect
magnetostrictive strain