Force between Two Bar Magnetsexamples|products|Murata Software Co., Ltd.

Example5 Force between Two Bar Magnets

General

  • The force between two magnets is analyzed.
     

  • The vectors of the magnetic field and the magnetic flux density, and the electromagnetic forces are solved.
     

  • Unless specified in the list below, the default conditions will be applied.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

Item

Settings

Solvers

Magnetic Field Analysis [Gauss]

Analysis Type

Static analysis

Options

N/A

Model

Two solid bodies of magnets (mag1, mag2) are defined.

The magnetizing direction of the magnets is in the +Z direction by default.

Therefore, the top of the magnet is the N pole and the bottom is the S pole.

 

Mesh size is set at 0.5[mm] as the magnetic field changes drastically between the magnets.

 

  • Set the gap between the bodies and mesh size properly to obtain valid calculation results.
    See [Calculation of the Electromagnetic Force] for more details.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

mag1

mag

2/Solid

mag2

mag

* Available from the Material DB

 

The material properties are set up as follows:

Material Name

Tab

Properties

mag

Permeability

Material Type: Permanent Magnet

Magnet

Magnetization Strength: 0.5

Boundary Conditions

No setting.

Results

To see the electromagnetic force, go to the [Results] tab

 

 

 and click [Table] .

 

 

Two magnets are pulling each other with the approximate force of 2.4[N] in the Z direction.

 

The vectors of the magnetic field are shown below.

The strong magnetic field is generated in the gap between the magnets.

 

In the figure below, the magnetic field of the inside of magnets is shown and that in the air is hidden.

You can see that the direction of the magnetic field at the magnet poles is opposite to that in the air.

 

The vectors of the magnetic flux density are shown below.

Inside the magnet, the directions of the magnetic flux are the reversal of those of the magnetic field.