Variations

For tolerance analysis, you should specify how much does the actual value of physical property can differ from nominal, or how much does the size or position of some part of the model geometry can differ from nominal.

To describe it, it is necessary to specify the variations. Each variation is a description of a geometry transformation or change of material properties of one QuickField Model objects.

For example, typical variation could be "Block "Alnico Up" can be moved in any direction for a distance not more then 1 mm". Or, another typical example: "Coercive force of the magnet "Alnico Up" can be changed for amount not more then 3% of nominal".

There are two kinds of variations: Geomeric variation and Property variation.

Geometric Variation
With this variation, we specify how much does the geometry of the problem can be changed. We can specify:

• One or several labels to be moved
  Specify the blocks, edges and vertices to be moved.

• Type of move
  Displacement, Rotation and Scaling are supported.

  For displacement, there are two option available - you can specify move in a fixed direction, and specify the maximum displacement vector, or you can specify move in any direction and specify the maximum distance.

• Parameters for the operation
  For Displacement operation in fixed direction you should specify dx and dy - maximum displacement vector

  For Displacement operation in any direction, you should specify dr, a maximum displacement distance.

  For Rotate operation you should specify the rotation center coordinates x, y and the maximum rotation angle.

  For Scale operation you should specify x and y for the center and the maximum scale factor.

Property Variation

Specify how much can this property be changed. You should specify:

• Label
  Property will be changed for this label.

• Property
  You should specify name of the property to change. You can specify most of the properties supported by QuickField. (But see also remark below).

• Variation
  You should specify maximum amount to increase or decrease the property. You can use option Specify variations in percents.

Note. LabelMover cannot apply tolerance analysis to the library data. If you want to study variations for the properties of the label kept in the Library Data file, you need to copy this label to the Data file first.

Technical Note. Maximum deviation defined for variation is actually equal to 3*σ where σ is a standard deviation. See Using 3*Sigma for Normal Distribution in Theoretical Description for more details.

For more information please see
Tolerance Analysis Overview
Theoretical Description for Tolerance Analysis