Stretch Forming Geometry

Following are some of the important GCD types identified by geometry extraction for the Stretch Forming process group:

• Blank: as with other sheet metal process groups, there is a single Blank GCD that represents the flattened part. The flattening calculation uses a finite element analysis derived from the part’s CAD model and the properties of the selected material. (Note that if you change the selected material and re-cost, you must be CAD-connected, since flattening must be re-calculated and geometry re-extracted.) See Blank GCD for more information.

• Forms: extracted GCDs include three types of Form GCD (which differ with regard to the Sub Type property):

o EMBOSS forms (created by the Stretch Form process)

o CURVED_BEND forms (assumed to be hand formed)

o STAMP forms (areas of thickness reduction that are assigned to chemical milling, when the Chemical Milling process routing is manually selected)

• Ram Direction: in the Stretch Forming process group, this GCD represents a candidate for the direction from which the ram approaches the stock during the stretch forming process. In some cases (for example, for some saddle-shaped parts), the direction that is the opposite of the ram direction is also a candidate for the direction from which the ram approaches. See Ram Direction GCD for more information.

• Xsection: there are two Xsection GCDs that represent cross-sections of the part. One Xsection is aligned with the direction of least sharp bend, and the other Xsection is orthogonal to it. The properties of the Xsections help the cost model determine feasible stretching directions for the part, as well as the required pull force. See Xsection GCDs for more information.