• Blank GCD: this GCD represents the flattened part. aPriori calculates the blank’s outline (including any addendum deemed necessary by the cost model), and determines an efficient nesting of the blank on sheet or coil stock. Blanks are created by Router Cut, Laser Cut, or Offline Blanking, and then loaded onto the Hydroforming machine.

• Xsection GCD: these GCDs represent part cross-sections in planes orthogonal to the ram direction. The cost model examines their arrangement and widths in order to evaluate process feasibility and determine the number of draws required for the part.

• Ram Direction GCD: this GCD represents the direction (relative to the part) from which the bladder approaches the blank. aPriori’s choice of ram direction reflects how the part is assumed to be oriented in the hydroforming press. The Ram Direction points up, from the lower tray or punch of the machine toward the bladder. You can use the Ram Direction tool to override aPriori’s choice of ram direction (for example, in order to ensure that the blank can lie flat on a large area of the tool before forming).

• Main Surface GCD: this GCD consist of a group of associated surfaces, and represents a portion of the part that retains a relatively stable orientation relative to the hydroforming press table throughout the forming process. Relations involving the MainSurface help the cost model to identify the part’s primary forms, and to determine which of the part’s holes can be created prior to forming.

• Form GCD: each of these GCDs is collection of surfaces that represents a feature that is created by forming, and is classified as either a curved bend or emboss. By using the Form Definition dialog, you can change a form’s classification or override the extracted surface groupings.

• StraightBend GCD: these GCDs are among the features that can be created by the forming tool in hydroforming. Properties that play an important role in the hydroforming cost model include Bend Direction and Bend Flap Size.