16. Element Properties

16. Element Properties#

Declares the items used to assign material properties to the mesh. Detailed definitions are provided below.

16.1 Volume Element Properties

16.2 Surface Element Properties

16.1.2 Volume Element Properties (Electric-Field Analysis)

Input settings#

16_Material_Properties JSON key: element properties object

EXTEND_TOTAL(16) When using COIL(17.1), extends the total-potential region by one layer into the reduced-potential region.

EXTEND_TOTAL_for_COIL(16) JSON key: when using COIL(17.1), extends the total-potential region by one layer into the reduced-potential region.

THIN_CRITERION(16) Applies THIN_ELEMENT to volume elements whose aspect ratio exceeds THIN_CRITERION.

Input format#

Text-format section
Fixed parameter set 1#
[row, col] = [1, 3]
Type=I
Text format#
* NO_MAT_IDS *  EXTEND_TOTAL *  NO_SMAT_IDS *
    I              I             I

JSON format#

JSON format from 2024.11#
"16_Material_Properties" :
{
    "EXTEND_TOTAL_for_COIL" : I,
    "THIN_CRITERION" : E,
    "16_1_3D_Element_Properties" :
    [
        {
            "MAT_ID" : I,
            "POTENTIAL" : I,
            "ElectricProperty" :
            {
                "conductivity" :
                {
                    "comment" : "SIGMA_XYZ for anisotropic, or isotropic SIGMA if not defined.",
                    "SIGMA" : E
                }
            },
            "MagneticProperty" :
            {
                "comment" : "MU_XYZ for anisotropic, or isotropic MU if not defined.",
                "MU" : E
            }
        },
        {
            "MAT_ID" : I,
            "POTENTIAL" : I,
            "ElectricProperty" :
            {
                "conductivity" :
                {
                    "comment" : "SIGMA_XYZ for anisotropic, or isotropic SIGMA if not defined.",
                    "SIGMA" : E
                }
            },
            "MagneticProperty" :
            {
                "comment" : "MU_XYZ for anisotropic, or isotropic MU if not defined.",
                "MU" : E,
                "BH_CURVE_ID" : I
            }
        }
    ]
}

Detailed description#

16_Material_Properties#

16_Material_Properties#
JSON key:

Element properties object

Text-format section
MAT_IDS (text format only)
Fixed parameter set 1#
[row, col] = [1, 1]
Type=I

Number of volume-element material IDs. The total number of properties assigned to volume elements in the input mesh (surface elements in two-dimensional analysis).

EXTEND_TOTAL (text format) EXTEND_TOTAL_for_COIL (JSON)#

EXTEND_TOTAL(16)#
EXTEND_TOTAL_for_COIL(16)#
Text-format section
Fixed parameter set 1#
[row, col] = [2, 1]
Total-potential region extension#

Setting value

Description

0: Default

Does not extend the total-potential region into the reduced-potential region.

1

Extends the total-potential region into the reduced-potential region.

When calculating nodal forces including conductor or magnetic-material surfaces, the surface nodes must be included in the total-potential region. If the surface is the boundary between the total-potential and reduced-potential regions, nodal forces cannot be calculated for nodes on that boundary.

Note

When calculating nodal forces including conductor or magnetic-material surfaces, the surface nodes must be included in the total-potential region. This is because nodal forces cannot be calculated for nodes on a boundary between the total-potential and reduced-potential regions.

Text-format section

NO_SMAT_IDS

Fixed parameter set 1#
[row, col] = [1, 1]
Type=I

Number of surface-property IDs. The total number of properties for surface-impedance surface elements, gap elements, and nonmagnetic thin-plate elements.

THIN_CRITERION#

THIN_CRITERION(16)#
Text-format section
Fixed parameter set 1#
[row, col] = [3, 1]
Type=E

* THIN_CRITERION * NO_MAT_IDS *
    E              I
* MAT_IDS *
    I

NO_MAT_IDS: number of volume-element IDs; MAT_IDS: volume-element IDs

Data type:

Real number (E)

Description:

THIN_ELEMENT is applied to volume elements whose aspect ratio (the ratio of the long side to the short side) is greater than THIN_CRITERION.

Note

When the aspect ratio of a volume element is greater than THIN_CRITERION, applying THIN_ELEMENT to the resulting thin element improves convergence degradation caused by the element and can improve computational accuracy.

It is effective when the magnetic flux density changes little between thin elements. Because its effect is small for thin elements on conductor surfaces where eddy currents occur, applying it to air regions is effective.