The plane in which the length of a curved sheet metal part remains unchanged is identified by the neutral phase. The portions on either side of this neutral phase become longer or shorter.
The location of this neutral phase relative to the material thickness ("T") is described in terms of a parameter known as the K factor. ANSI (American National Standard Institute) defines this K factor as the offset of the neutral phase relative to T, while DIN (Deutsche Industrienorm) defines the K factor as the offset of this neutral phase relative to T/2.
Both conventions are illustrated in the following figure.
You need to specify a K factor when working with sheet metal parts in Creo Elements/Direct Modeling.
Creo Elements/Direct Modeling uses the ANSI definition of the K factor.
To change the K factor (the Annotation module should be active),
1. Click Annotation and then, in the Setup group, click the arrow next to Dep View.
2. Click Create Flat. The Flat View dialog box opens.
In the basic Creo Elements/Direct Sheet Metal context, the K Factor is persistent data. When you change the K Factor value in the Flat View (under Annotation) dialog box, Fold/Unfold (under Sheets tab, Modify Sheet group) dialog box, or Unfold Parts (under Sheets tab, Parts group) dialog box, the change is made in all three of the dialog boxes.
Dep View.
Create Flat. The Flat View dialog box opens.