Object combinations

The option creates complex objects on the basis of previously-defined 2-dimensional objects. The option is available using either method:

Click Edit menu > Edit Solids and Faces > Object Combinations.
Click .

Note: The option is available for only the following structure types: plate, shell, and volumetric structure (solid).

These options let you combine previously-defined 2-dimensional objects (pipe surface, prism surface, arc, and so on) and 3-dimensional objects into complex objects. For 2-dimensional objects, operations are carried out on surfaces and not on volumetric (3-dimensional) objects.

The following operations on pre-defined objects are available in Robot:

logical options:
- With one operand
- With two operands
Cutting off

In the Robot, it is recommended to use 3- and 4-node surface elements. When 6- and 8-node surface elements are used for mesh generation, the cutting off option might not work correctly.

Note: The dialog appearance and available logical operations depend on whether Solid Modeler or internal mechanisms of Robot are used to generate Boolean objects.

Among logical operations, you can use the following logical operations (when applying the internal mechanisms of Robot):

Common part (A*B)
Sum (A+B)
Complement (A-B) - only for operations with 2 operands
Exclusive alternative ( A or B )

Among logical operations using Solid Modeler, you can use the following types of logical operations:

Intersection
Union
Partition
Subtraction - only for double-operand operations
Inclusion - only for double-operand operations
Partition (A-B) (B-A) (A*B) - only for double-operand operations.

Note: It is not recommended to apply Solid Modeler for the following structure types: plate, plane stress structure, plane deformation structure, and axisymmetric structures.

For logical operations using Solid Modeler, the dialog also contains the Minimize the number of faces option. When this option is selected, if you combine 2 solids Robot generates one common edge (common face) for a combined object (see the following image - face no.1).

When this option is cleared, a greater number of edges (faces) are generated. See the following example (faces 1, 2 and 3 are generated).

Note: For operations that combine planar objects (such as a plate or shell), you should not apply the Coons' meshing method. For this type of object, the Delaunay's method should be used.

The center of the dialog has Advanced settings, which opens an additional dialog. Clicking the "<<" button at the bottom of the Object Combinations dialog, enlarges the dialog. The additional field lets you enter the definition of the complex object. The definition covers:

Number of the complex object.
Numbers of the component objects making up the complex object.
Name of the logical operation.

Successive complex objects are displayed in the form of a tree.

To restore the original size of the dialog, click the ">>" button.