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Permeability Tab

The material's relative permeability is set on this tab.

It is in the [Edit Material Property] dialog box. See [How to Set Body Attribute/Material Property].

The isotropic/anisotropic and linear/nonlinear materials are set up on this tab.

The anisotropic material will have the anisotropy set on the Directivity tab.

Setting Items	Notes
Material Type	Available only for the static and transient analysis of the magnetic solver. ([Use the tensor permeability] is only option applicable to the electromagnetic analysis.) Soft Magnetic Material Analyzes the magnetic materials in general other than magnet. Input Parameters Soft Magnetic Material (with minor loop) Simulates the superimposed DC characteristics. The BH curve of the major loop is set on this tab. The BH curve of the minor loop is set on the Permeability (with minor loop) tab. See [Superimposed DC Characteristic Analysis] for more information. Available only for magnetostatic analysis. Input Parameters Permanent Magnet Analyzes magnet. Input Parameters Tensor Permeability Sets the analysis using the tensor permeability. Available only for the electromagnetic analysis. Input Parameters Magnetizing Material Sets the target for magnetization. Available only for the magnetic-transient analysis. Input Parameters Use Magnetization Result In the analysis where the magnetizing material mentioned above is used, the magnet is specified and its results are used. Available only for the magnetic-transient analysis. Input Parameters Permanent Magnet (Irreversible demagnetization taken into account) Available to take the irreversible demagnetization into account, which is caused when the working point goes beyond the knickpoint. The transient analysis continues until the steady-state is reached. It analyzes the extent of the demagnetization and how the magnet’s performance is degraded. The distribution of the demagnetization rate is output. This is available for the magnetic transient analysis only. Input Parameters Permanent Magnet (Demagnetization rate of the irreversible demagnetization result is used) Available to apply the analysis results of the irreversible demagnetization (demagnetization ratio distribution) mentioned above to the original magnet before demagnetization. Other analysis than the demagnetization is possible. For instance, thermal-demagnetization analysis can be performed, where the demagnetization at high temperature is analyzed by [Permanent Magnet (Irreversible demagnetization taken into Account], and the calculation results of demagnetization rate are used for the magnet characteristics at ambient temperature. Available only for the magnetic transient analysis. Input Parameters
Soft Magnetic Material
	Magnetization Characteristic Type	Available for the magnetic analysis. Linear (Constant) Available for the constant relative permeability. B-H Curve Defines the relative permeability. Click to open the B-H Curve Table. Fill in the table with the magnetic field and the magnetic flux density. Enter the initial magnetization characteristics of the B-H curve (the first quadrant). Click the Graph button to see the graph of entered data. When the Linear(Constant) is selected in the Magnetization Characteristic Type, magnetic saturation is not taken into account. If magnetic saturation or B-H curve needs to be taken into account, switch the Magnetization Characteristic Type to B-H Curve and enter the B-H curve data. In this case, however, calculation will take longer time as this is a nonlinear calculation. If the magnetization characteristic is defined by B-H curve or M-H curve, calculation is nonlinear. Nonlinear calculation may not converge. In such case, refer to "If the Nonlinear Calculation (B-H Curve) Does Not Converge " If B-H curve is selected in the harmonic analysis, pseudo-nonlinear analysis is executed. For accuracy, transient analysis, which performs strict nonlinear calculation, gives higher accuracy. The calculation time of the transient analysis tends to be longer.
	Anisotropy	Sets either Isotropic or Anisotropic.
	Frequency Dependency	Available only for electromagnetic-harmonic analysis. Select either Yes or No. If Yes is selected, by clicking , [Frequency-Relative Permeability] Table and [Frequency-Relative Permeability (anisotropic)] Table will show up. Enter the frequencies, the corresponding relative permeabilities, and magnetic loss tangents (tanδ). If The conductor bodies thicker than the skin depth constitute the boundary condition is selected on the Mesh tab of the analysis condition, the surface impedance may be set on the surface of the conductor. In such a case, the frequency dependency is not taken into account as the frequency-dependent material is not supported by the surface impedance setting function.
	Temperature Dependency	Selectable for the magnetic harmonic - thermal coupled analysis. Select either Yes or No. If Yes is selected and is clicked, the [Temperature-Relative Permeability] Table will appear. Fill in the table. If Temperature Dependency is selected, the analysis becomes bidirectional between magnetic and thermal analysis. The calculation will be repeated until it reaches the convergence. The calculation time, therefore, will be longer than the case of no time dependency.
	Relative Permeability	It can be entered only when Linear (Constant) is selected for the magnetization characteristic type and Isotropic is selected for Anisotropy. The significand is a real number greater than 0.
	Relative Permeability Matrix	Available only if Linear (Constant) is selected for the magnetization characteristic type and Isotropic is selected for Anisotropy. The significand is a real number equal to or greater than 0. It is not allowed to enter 0 in (x, x), (y, y), and (z, z). Direction of the anisotropic material depends on the setting on the [Direction] tab of body attribute. With the default setting on the Direction tab, (x, y, z) in the above figure matches with (X, Y, Z) of the modeling window.
	Magnetic Loss tangent	Available for the electromagnetic analysis only. However, the electromagnetic-transient analysis is not supported. Magnetic loss tangent (tanδ) represents the ratio of the real part to the imaginary part of the complex permeability. Complex permeability μ is represented as below where μr is the relative permeability, μ0 is the permeability in the vacuum, and j is the unit for imaginary number. μ = μr × μ0 × ( 1 - j tanδ)
Soft Magnetic Material (with minor loop)	The BH curve of the major loop is set on this tab. The BH curve of the minor loop is set on the Permeability (with minor loop) tab. For setting the BH curve of the major loop, refer to [Soft Magnetic Material] mentioned in the above. See [Superimposed DC Characteristic Analysis] for more information.
Permanent Magnet
	Magnetization Characteristic Type	Linear (Constant) Sets the constant magnetization strength. B-H Curve Defines the magnetization strength. Click to open the B-H Curve Table. Fill in the table with the magnetic field and the magnetic flux density. Demagnetization Curve: Enter the second quadrant of the B-H curve (the third quadrant may be included in some cases) M-H Curve Defines the magnetization strength. Click to open the M-H Curve Table. Fill in the table with the magnetic field and the magnetization. Demagnetization Curve: Enter the second quadrant of the M-H curve (the third quadrant may be included in some cases) Click the [Graph] button to see the graph of entered data. For the data out of the table range, the data of nearest 2 points will be extended linearly. If the magnetization characteristic is defined by B-H curve or M-H curve, calculation is nonlinear. Nonlinear calculation may not converge. In such case, refer to "If the Nonlinear Calculation (B-H Curve) Does Not Converge "
	Magnetization Strength (Residual Magnetic Flux Density)	Available only if Linear (Constant) is selected for the magnetization characteristic type. Sets the magnetization strength of magnet. Normally, residual magnetic flux density (magnetic flux density when the magnetic field is 0) is entered.
	Relative Permeability	Available only if Linear (Constant) is selected for the magnetization characteristic type. Enter the relative permeability (recoil relative permeability) of magnet. Generally, it is 1.0 to 1.20.
Tensor Permeability	Enter the [Properties of Ferrite] in addition to the inputs mentioned in [Permanent Magnet] above. Used only when the ferrite is involved in the electromagnetic-harmonic analysis. The tensor permeability is calculated from the magnetostatic field specified on the Static Magnetic Field tab, the magnetization strength, and ⊿H and g coefficient specified here. (Tensor Permeability of Ferrite) (Tensor Permeability of Ferrite)
Magnetizing Material
	Initial Magnetization Characteristics	Specified by the B-H curve. Click to open the B-H Curve Table. Fill in the table with the magnetic field and the magnetic flux density. By clicking the Graph button, the graph for the nonlinearity based on the entered data will show up. At least two data for [Magnetic field] and [Magnetic flux density] respectively are required to draw a graph.
	Magnetization Characteristics	Purple line: Initial magnetization curve Red line: Return curve Hmag: Magnetization field Bmag: Magnetization flux density Br: Residual magnetic flux density Br_Full: Residual magnetic flux density at the perfect magnetization (magnetization ratio: 1.0) Hc: Coercive force Hcr_Full: Coercive force at the perfect magnetization (magnetization ratio: 1.0) magratio: Magnetization ratio μr: Recoil relative permeability As magnetization characteristic, the return curve after the magnetization field is applied (red line shown above) is defined by the magnetization ratio curve. In the magnetization analysis, the magnetization strength is determined as follows. Calculate the magnetic field distribution by utilizing the initial magnetization characteristics for each time step. Determine the magnetized field (Hmag) for each element of the magnetizing material. The intensity of the magnetic field is obtained for each timestep. At some timestep, the intensity drops. The magnetization field is determined by the intensity of the magnetic field at a timestep just before it drops. *If the magnetization strength does not go down until the final step, the magnetic field at the final step is the magnetization field. The same applies to the steady-state analysis. The magnetization ratio and the recoil relative permeability are obtained from the magnetization field (Hmag) and the magnetization ratio curve. The magnetization vectors (=residual magnetic flux density:Br) are given by the following methods (1) Normalization with the residual magnetic flux density(Br): Calculates Br with the magnetization rate and the value of Br at magnetization ratio of 1.0. (Br = magnetization ratio x Br at magnetization ratio of 1.0) (2) Normalization with the coercivity(Hc): Calculates Hc with the magnetic flux density and the value of Hc at magnetization ratio of 1.0.(Hc = magnetization ratio x Hc at magnetization ratio of 1.0 From the calculated Hc and recoil relative permeability, the red line can be drawn to obtain Br. Input parameters are as follows. Definition type of magnetization ratio The magnetization ratio curve is defined as the magnetization characteristic. Magnetization ratio is normalized by one of the following. Normalize with the residual magnetic flux density Normalize with the coercivity Magnetization Ratio Curve Enter the magnetization field (Hmag) and the magnetization ratio (magratio), and the recoil relative permeability (μr) in the table. If the magnetic field intensity is greater than the maximum value of the magnetization field which is defined in this table, magnetization field=last value (maximum value) in the table. The magnetization ratio and the recoil relative permeability also refer to the last values in the table. Residual magnetic flux density with magnetization ratio of 1.0 / Coercivity with magnetization ratio of 1.0 Enter the residual magnetic flux density and coercivity at the time of full magnetization. For the analysis using the magnetization analysis results, the magnetization vectors and the recoil relative permeability (μr) are used. (Slope of the line is treated as constant)
Use Magnetization Result
	Specify the magnetization analysis results to use	The magnetization analysis results to use are specified. Specify analysis model The result of the analysis model in the same project is used. The analysis model is selected from the same project. Specify pdt File Specifies the results file directly. Press Browse button to specify the pdt file. Z coordinate of the reference plane It is specified to use the 3D analysis results for the 2D analysis. It specifies which plane of the 3D analysis is used.
	Correction of Magnetization Distribution	The magnitude of the magnetization can be corrected. No correction is applied at 1.0.
Permanent Magnet (Irreversible demagnetization taken into account)
	Magnetization Characteristic Type	As in the case of [Permanent magnet], “Linear (Constant)” is not selectable. B-H Curve Defines the magnetization strength. Click to open the B-H Curve Table. Fill in the table with the magnetic field and the magnetic flux density. Demagnetization Curve: Enter the second quadrant of the B-H curve (the third quadrant may be included in some cases) M-H Curve Defines the magnetization strength. Click to open the M-H Curve Table. Fill in the table with the magnetic field and the magnetization. Demagnetization Curve: Enter the second quadrant of the M-H curve (the third quadrant may be included in some cases) Click the [Graph] button to see the graph of entered data. Try to make the curve as smooth as possible for the B-H curve (or M-H curve). For the straight line, only two points at both ends are enough to enter. More detailed data are necessary for the corner where the knickpoint exists. If the measured data is input as it is, the microscopically uneven curve is created due to the measurement error. It is directly reflected in the demagnetization rate, and the accuracy is deteriorated. (The result appears as if it is slightly demagnetized though it is not in reality) The red points in the graph above show the trajectory of the working point (H, B) at a certain point inside the magnet. In the transient analysis, the branch point is revised to form the new trajectory of the working point (H, B). The slope of the (H, B)trajectory after revising the branch point is set to the same slope as the recoil permeability at H = 0 in the demagnetization curve which is shown blue in the graph above.
Permanent Magnet (Irreversible demagnetization rate of the analysis results are used)
	Magnetization Characteristic Type	Linear (Constant) Sets the constant magnetization strength. B-H Curve Defines the magnetization strength. Click to open the B-H Curve Table. Fill in the table with the magnetic field and the magnetic flux density. Demagnetization Curve: Enter the second quadrant of the B-H curve (the third quadrant may be included in some cases) M-H Curve Defines the magnetization strength. Click to open the M-H Curve Table. Fill in the table with the magnetic field and the magnetization. Demagnetization Curve: Enter the second quadrant of the M-H curve (the third quadrant may be included in some cases) Click the [Graph] button to see the graph of entered data.
	Magnetization Strength (Residual Magnetic Flux Density)	Available only if Linear (Constant) is selected for the magnetization characteristic type. Sets the magnetization strength of magnet. Normally, residual magnetic flux density (magnetic flux density when the magnetic field is 0) is entered.
	Relative Permeability	Available only if Linear (Constant) is selected for the magnetization characteristic type. Enter the relative permeability (recoil relative permeability) of magnet. Generally, it is 1.0 to 1.20.
	Specify the demagnetization rate distribution (results of the irreversible demagnetization analysis) to use.	Specifies the analysis results of the irreversible demagnetization to use (analysis result of [Permanent Magnet (Irreversible demagnetization rate of the analysis results are used]). Of the specified results, only demagnetization rate distribution is used for the magnet characteristics of the original magnet before magnetization. The magnetization is multiplied by (1-γ), where γ is demagnetization rate in the original magnet before demagnetization. Specify Analysis Model Uses the result of the analysis model in the same project. The analysis model is selected from the same project. Specify pdt File Specifies the results file directly. Press Browse button to specify the pdt file.