A Tube Selection Rule is a cylinder of variable axial direction with a constant inner and outer radius. The longitudinal direction is defined by an Edge Set, and the radii define the diameters of the inner and outer cylinder. All elements between the inner and outer radius are selected if Include Rule Type is enabled (shown below in Figure 2.51: Tube Selection Rule Properties). Otherwise the inverse selection is used.
Note: The Variable Offset Selection Rule allows the definition of a tube with a variable radius.
Tube Selection Rule settings are:
Edge Set: Defines the center line (longitudinal direction) of the tube.
Outer Radius: Defines the outer radius of the tube.
Inner Radius: Defines the inner radius of the tube.
Include Rule Type: If enabled (as shown above), elements inside the tube will be selected. If not enabled, elements outside the tube will be selected.
Extend Endings: Enable this option to extend the endings of the tube.
Symmetrical Extension: If enabled, the length of the extensions will be equal on both sides.
Head: The free end which is closer to this point becomes the head of the tube. It is only needed if Symmetrical Extension is disabled.
Head Extension: Defines the length of the extension at the head of the tube. If Symmetrical Extension is enabled, it defines both sides.
Tail Extension: Defines the length of the extension at the tail of the tube if Symmetrical Extension is disabled.
Notes:
An extension set to zero or a negative automatically disables the feature at the corresponding side.
When the end of a tube is extended, the extension is oriented in the same direction as the last edge segment.
