If you select the Sweep method, a swept mesh is forced on “sweepable” bodies (p. 245) (including axis-sweepable bodies, which are not displayed when you use the Show Sweepable Bodies feature). The mesher will fail if a swept mesh cannot be generated on a body with a Sweep Method control.
Use the Sweep option for any of the following situations:
• A swept mesh is required.
• You want a swept mesh on a model that revolves around an axis where the source and target faces share topology.
When you choose the Sweep option, the Details View expands to include additional settings, many of which are unique to this option. For basic usage that involves obtaining a swept mesh, the procedure is to apply a Method Control to one or more bodies, set Method to Sweep, and accept the default values of the various settings.
For advanced or specialized usage such as meshing thin models or axis sweeping, adjust the settings as needed. The following is a description of each of these settings.
• Element Midside Nodes - Refer to Method Controls and Element Midside Nodes Settings (p. 156).
• Src/Trg Selection - Defines the source and target selection type according to the following choices:
– Automatic - The program determines the best source and target for the body.
– Manual Source - You select the source and the program determines the target. This choice is useful when there are multiple source target pairs and you want to specify the source in order to get the correct bias through the sweep direction. Another application is when your cross section is changing and the mesh quality would be better when sweeping from one side vs. another.
– Manual Source and Target - The sweeper will revolve the mesh around common edges/vertices. This choice is useful when you want to sweep a body where the source and target faces share vertices and/or edges.
– Automatic Thin (p. 252) - This choice is for thin models and thin sheet metal parts, or any application where you want one hex or wedge through the thickness, in preparation for using the Mechanical APDL application's SOLSH190 element. (See the description for this element in the Element Reference within the Mechanical APDL help.) For this choice, the face with the largest face area is selected as the master source and the algorithm determines the rest of the source faces. For multibody parts, only one division through the thickness is possible. For single body parts, you can define multiple elements through the thickness using the Sweep Num Divs control. Biasing is not available. An Element Option setting is included that instructs the solver to use the Solid Shell element where possible, or to always use a Solid element.
– Manual Thin (p. 252) - The same restrictions apply as described above for Automatic Thin. However, with this choice, you can do any of the following:
→ Pick one source face and allow the program to determine the rest.
→ Pick all of the source faces and allow the program to do nothing but mesh the source faces and sweep them to the target.
→ Pick multiple source faces and mesh one target face.
Note
→ The Sweep mesh method does not support the Manual Source, Manual Source and Target, or Manual Thin settings for Src/Trg Selection if Sweep is applied to more than one part, even if you suppress all of the other parts.
→ In some cases, the thin model sweeper may want to swap source and target faces based on meshing conditions in neighboring bodies. In such cases, a warning message will be issued to alert you.
For example, if you are mixing a patch independent mesh method (i.e.,Patch Inde-pendent tetra (p. 160) or MultiZone (p. 184)) with the thin model sweeper to mesh bodies in a multibody part, the thin model sweeper may need to swap the source and target faces in order to respect protected topology in the neighboring bodies. If there is protected topology on both sides of the body that is scoped for thin sweep, the side with the largest number of faces is selected as the source face.
→ To make source/target face selection easier, select Annotation Preferences from the Toolbar and then deselect Body Scoping Annotations in the Annotation Preferences option box to toggle the visibility of annotations in the Geometry window. For example, after scoping Sweep to a body, the body will be displayed using a blue solid annotation. Turn off the body scoping annotations; then select the source/target faces. For picking internal faces, the Hide Faces right-click option may help you to see inside a body. For example, you can select ex-ternal faces in the Geometry window and then use the Hide Faces option to hide the selected faces (making it easier to select the internal faces).
Refer to Considerations for Selecting Source Faces for the Thin Model Sweeper (p. 253) for details.
• Free Face Mesh Type - Determines the shape of the elements used to fill the swept body (pure hex, pure wedge, or a combination of hex/wedge). Allows you to choose All Tri, Quad/Tri, or All Quad meshing when Src/Trg Selection is Automatic, Manual Source, or Manual Source and Target. Allows you to choose Quad/Tri or All Quad meshing when Src/Trg Selection is Automatic Thin or Manual Thin. The default in all cases is Quad/Tri.
Note
– If the source face is also a side face of another body, the face will always be quad mapped.
– When Free Face Mesh Type is set to either Quad/Tri or All Quad and the source face can be mapped meshed, the face will sometimes be mapped meshed even if it means applied sizing controls (such as Contact Sizing (p. 209),Sphere of Influence (p. 201), etc.) will be ignored.
– In some cases when Src/Trg Selection is set to Automatic, the source face that is selected by the software must be quad mapped in order for the sweep method to be successful. In these cases, the value that is specified for Free Face Mesh Type may be ignored.
• Type - Allows you to specify a Number of Divisions or Element Size through the sweep direction. When sweeping generalized bodies that share faces, the Element Size is a soft constraint on interval assignment and the Number of Divisions is a hard constraint. If you have conflicting Number of Divisions constraints, the sweeper will fail and yield a message. To obtain a regular mesh in the sweep direction, the guiding edges must have consistent lengths. You can define virtual split edges to achieve consistent lengths for these edges (see Creating and Managing Virtual Split Edges (p. 419)). Also see Sizing Control (p. 196) for more in-formation.
• Sweep Bias Type - Specify bias in the same manner as edge biasing for the Bias Type setting in a Siz-ing (p. 196) mesh control. There is no graphical feedback for biasSiz-ing on a Method control. BiasSiz-ing direction is based from the source to the target.
• The Constrain Boundary setting is available for multibody parts only (both for general sweeping and thin sweeping). Specify whether you want to allow the mesher to split the elements at the boundary of a swept mesh region to aid in meshing. You can choose Yes (constrain boundary; no splitting is allowed) or No (do not constrain boundary; splitting is allowed). Choosing Yes prevents tets from entering the swept body.
The default is No.
Note
• For gasket simulations, set the Stiffness Behavior of the body to Gasket and proceed with ad-justing mesh settings as described in the Gasket Meshing section located under Gasket Bodies in the Mechanical application help.
• In models with swept regions, the Size Function will affect the mesh gradation in the swept region.
You can override this effect by specifying any Sweep Bias value (including a value of 1), Sweep Element Size value, or Sweep Num Divs value in the Details View when defining the sweep method.
• There is a system limitation when using the sweep method with the Size Function (p. 69). The Size Function may have nodes slightly off because the spacing is queried. The sweeper then tries to match that spacing, which may lead to unexpected mesh results.
• If you apply a local Sizing control (p. 196) to a solid body with a Method control set to Hex Dominant (p. 180) or Sweep (p. 181), or to a sheet body with a Method control set to Quadrilat-eral Dominant (p. 193), a near uniform quadrilatQuadrilat-eral mesh will result on all affected faces on a body meshed with Hex Dominant, on the source face meshed with Sweep, and on all affected faces meshed with Quadrilateral Dominant. To obtain even more of a uniform quadrilateral mesh, set the Behavior (p. 203) of the Sizing control to Hard.