Create the Magnetostriction Interface and Define Domains
A magnetostriction problem can be set up in different ways:
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By selecting either Piezomagnetism or Nonlinear Magnetostriction from the Model Wizard,
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By choosing either Piezomagnetism or Nonlinear Magnetostriction from the Add Physics menu when working in an existing model, or
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By adding the corresponding coupling features to create the coupling manually.
In the first two cases, by default all the domains in the model are assumed to be magnetostrictive materials.
Piezomagnetism
When setting up the problem manually (that is, by adding single physics interfaces one at a time) both Solid Mechanics and Magnetic Fields interfaces should be added. Then, you have to specify which domains are in each physics, and which domains are to be modeled as piezomagnetic materials.
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On the Solid Mechanics interface Settings window, locate the Domain Selection section. Select the domains which undergo structural deformation, including the piezomagnetic material domains.
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Go to the Solid Mechanics > Piezomagnetic Material node. If it is not yet available, add such node. Select the domains where the piezomagnetic effect applies. You find all the necessary material data inputs within the Piezomagnetic Material. This includes the elasticity, magnetic permeability and coupling matrices. Nonpiezomagnetic domains can be modeled using any other available structural material model.
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Go to the Magnetic Fields node and under Domain Selection select the domains the magnetics equations must be solved. These domains include all the piezomagnetic domains, and any other magnetic domains.
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Go to the Magnetic Fields > Ampère’s Law, Piezomagnetic node. If it is not yet available, add such node. Select the domains where the piezomagnetic effect needs to be modeled.
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A Multiphysics > Piezomagnetism node is already present if the coupling was added using either the Model Wizard or Add Physics window. If the model is set up manually (that is, single physics interfaces are added), right-click the Multiphysics Couplings node to add a Piezomagnetism coupling. If several Solid Mechanics or Magnetic Fields interfaces are present, select the correct ones. By default, the model will be solved as fully coupled. Alternatively, on the Piezomagnetism coupling node, you can select to include only either Joule effect or Villari effect. Confirm that all the domains where the piezomagnetic material is present are selected.
Only domains that have both Ampère’s Law, Piezomagnetic selected in the Magnetic Fields interface and Piezomagnetic Material selected in the Solid Mechanics interface are applicable in the selection for Piezomagnetism coupling. The selection of this multiphysics coupling node cannot be edited directly.
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Confirm that remaining domains are well assigned:
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Solid and magnetic domains: In these domains, the magnetics and structural problems are solved independently without any piezomagnetic coupling. This represents deformable magnetic materials for which such coupling is negligible. Exclude such domains from the selections for all Ampère’s Law, Piezomagnetic, and Piezomagnetic Material nodes under the corresponding interfaces.
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Solid–only domains: In these domains, only mechanical phenomena are modeled, and the magnetics phenomena are neglected. This represents deformable solid nonmagnetic materials. Exclude such domains from the selection in the Magnetic Fields interface.
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Magnetics-only domains: Those domains are nonsolid. This is typically the case of air, in which the magnetics is solved but not mechanics. Exclude such domains from the selection in the Solid Mechanics interface.
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Nonsolid and nonmagnetic domains: In those domains another physics is solved. Typical examples are acoustic domains and fluid flow domains, which might be present in certain multiphysics application. Exclude such domains from the selections on both Magnetic Fields and Solid Mechanics interface nodes.
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Piezomagnetic Material
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Ampère’s Law, Piezomagnetic
Nonlinear Magnetostriction
When setting up the problem manually (that is, by adding single physics interfaces one at a time) both Solid Mechanics and Magnetic Fields interfaces should be added. Then, you have to specify which domains are in each physics, and which domains are to be modeled as magnetostrictive materials.
Instead of Magnetic Fields interface, you can also use Rotating Machinery, Magnetic interface.
1
On the Solid Mechanics interface Settings window, locate the Domain Selection section. Select the domains which undergo structural deformation, including the magnetostrictive material domains. The following structural material nodes are supported to represent the magnetostrictive domains: Linear Elastic Material and Hyperelastic Material (available with the Nonlinear Structural Materials Module).
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Go to the Magnetic Fields node and under Domain Selection select the domains the magnetics equations must be solved. These domains include all the magnetostrictive domains, and any other magnetic domains.
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Go to the Magnetic Fields > Ampère’s Law, Nonlinear Magnetostrictive node. If it is not yet available, add such node. Select the domains where the magnetostriction effect needs to be modeled. You can specify the magnetization model and enter the related material data on the node.
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A Multiphysics > Nonlinear Magnetostriction node is already present if the coupling was added using either the Model Wizard or Add Physics window. If the model is set up manually (that is, single physics interfaces are added), right-click the Multiphysics Couplings node to add a Nonlinear Magnetostriction coupling. If several Solid Mechanics or Magnetic Fields interfaces are present, select the correct ones. On the coupling node, you can also select the magnetostriction model depending on the material symmetry and enter the corresponding coupling data. By default, the model will be solved as fully coupled. Alternatively, on the Nonlinear Magnetostriction coupling node, you can select to include only either Joule effect or Villari effect. Select only the domains where the magnetostrictive effect needs to be modeled.
On the Nonlinear Magnetostriction coupling node, the applicable domains in the selection are only domains that have both Ampère’s Law, Nonlinear Magnetostrictive selected in the Magnetic Fields interface and Linear Elastic Model (or Hyperelastic Model) selected in the Solid Mechanics interface.
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Confirm that remaining domains are well assigned:
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Solid and magnetic domains: In these domains, the magnetics and structural problems are solved independently without any magnetostriction coupling. This represents deformable magnetic materials for which such coupling is negligible. Exclude such domains from the selection in the Nonlinear Magnetostriction coupling node.
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Solid–only domains: In these domains, only mechanical phenomena are modeled, and the magnetics phenomena are neglected. This represents deformable solid nonmagnetic materials. Exclude such domains from the selection in the Magnetic Fields interface.
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Magnetics-only domains: Those domains are nonsolid. This is typically the case of air, in which the magnetics is solved but not mechanics. Exclude such domains from the selection in the Solid Mechanics interface.
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Nonsolid and nonmagnetic domains: In those domains another physics is solved. Typical examples are acoustic domains and fluid flow domains, which might be present in certain multiphysics applications. Exclude such domains from the selections in both Magnetic Fields and Solid Mechanics interfaces.
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Ampère’s Law, Nonlinear Magnetostrictive