Defining Pipe Relationships

Pipe Relationships can be defined between two objects that have positional and directional information. Typically, this means lines, cylinders, or planes. The particular type of object does not matter—as long as the object properly describes the pipe’s position and orientation. When a pipe relationship is created, a tube representing the allowable cut region and ID/OD appears in the graphical view, and the Pipe to Pipe Relationship dialog is displayed.

The first step is to define the properties of each pipe segment:

A pipe relationship will supply several forcing functions to an optimization:

After defining the characteristics of the pipe segments, the weighting factors for the relationship may be modified, if desired. Typically, the default values are sufficient:

To Solve a Pipe Relationship:

  1. First take a moment to think about the assembly. If there is more than one pipe segment that will be assembled (that is, if there will be more than one independently moving object in the optimization), then each moving object (pipe segment) should be placed into its own collection. This includes the objects defining the pipe endpoint, the pipe surface/cylinder, and anything else you want to rigidly move with that pipe segment. In this situation, you must use Relationships > Move Col- lections by Minimizing Relationships in step 7 below.

  2. Create a primitive SA object with directionality (circles, lines, cylinders, or planes—but circles are preferred) to represent the end of each pipe opening in the assembly. Each object’s normal direction must face the mating pipe segment as depicted below.

  1. From the menu, select Relationships > Pipe Fitting.

  2. Select the object (i.e. circle) describing the first pipe segment, then the second.

  3. In the Pipe to Pipe Relationship dialog, click the Edit button for each pipe segment and define the ID, OD, and begin/end values for the allowable cut region.

  4. If any pipe ends are already cut, create a frame representing that pipe end (usually Construct > Frame > On an Object is appropriate) and then click the Force CUT to Frame button.

  5. Create any other conventional relationships governing the alignment, if applicable.

  6. Solve the relationship using Alignments > Relationship Fit > Move Objects by Minimizing Relationships or > Move Collections by Minimizing Relationships, as applicable. Enable/disable and adjust the weights on all relationships as desired.