Tools for the creation of the magnetic property B(H): specificities of the numerical models (splines)
Introduction
This section presents the creation of the magnetic property B(H) in the case of numerical models.
The main information refers to:
 the description of the numerical models (standard spline and smoothed spline)
 the operating mode for the creation of a magnetic property B(H) in the case of a numerical model
Two modes of description
It is possible to distinguish between two modes of description for the model:
 the standard spline mode
 the smoothed spline mode
Mode spline standard
In the standard spline mode, the curve B(H) is defined by the assembly of points entered by the user.
The user enters the pair of values B,H observing the following rules:
 the pair of values B,H must respect an increasing sequence and begin with (0,0)
 a sufficient number of points must be given to describe all the curve B(H) up to saturation (the number can vary from 4 to 200)
 the last points must approximate an asymptote having the slope μ_{0}
μ_{incremental}(H)
Smoothed spline mode
In the smoothed mode, the definition of the curve B(H) is simplified. This mode of definition requires fewer points than the standard spline mode.
The curve B(H) is divided into three parts:
 the first part is a homographic function passing through zero and describing the bend of the B(H) dependence. It is defined by a pair of values (B,H) provided by the user and it ends at the last pair of values provided by the user
 the second part is a homographic function for tangent connection to the first part and to the last part of the curve B(H)
 the third/last part is a straight line of slope μ_{0}, which has as an ordinate at the origin H = 0 the magnetization to saturation J_{s}
 the pair of values (B,H) must respect an increasing order
 the user must describe the first part of the B(H) curve, up to the bend, with:
 5 to 8 representative points
 3 points imposed on this curve
 the user must enter the value of the saturation magnetization Js in order to define the asymptote part of the B(H) curve
Operating mode
To create a magnetic property B(H) with a numerical model, follow the operating mode below:
Step  Action 

1 
In the my_base base of material

2 
In the tab B(H)

3 
In the zone of the models

4 
In the zone for the description of the model

→  Open the assistant … 
External data / wizard  

Step  Action 
1. External data 
If the external data exist … If not:

2. Smoothed spline 
If smoothed spline:

3. Synthesis  Click on Next 
External data …
The following table resumes what was described before:
Model  Points (external data)  Points (spline curve) 

Standard spline  The external data correspond to the points of passage of the curve (accessible and modifiable points)  The points of the curve standard spline correspond to the external data (equality) 
Smoothed spline  The external data correspond to the initial points (accessible and modifiable points)  The points of the smoothed spline curve correspond to the points calculated after the smoothening of the external data 
Advice
If you work in the smoothed mode, you should not forget to tick the box at each modification.