Extract Midsurfaces

Use the Midsurfaces: Automatic tool to extract the midsurface of sheet metal stampings, molded plastic parts with ribs, and other parts that have thickness clearly smaller than width and length.

  1. From the Geometry ribbon, click the Midsurfaces > Automatic tool.


    Figure 1.
  2. Optional: On the guide bar, click to define midsurface options.
  3. Select surfaces or thin solids.
  4. Extract midsurfaces.
    • Extract the midsurface from all selected solids/surfaces by clicking Midsurface on the guide bar.
    • Extract the midsurface from individual solids/surfaces by left-clicking on a selected solid/surface.
    Tip: When selecting surfaces, you can easily select opposite surfaces by right-clicking and selecting the Select Opposite option from the context menu.
The original geometry that you selected to extract the midsurface from remains unchanged, and the new geometry that represents the midsurface is placed in the component specified by the Destination component option.

Midsurfaces: Automatic Tool

An overview of the Midsurfaces: Automatic tool.



Figure 2.

Use the Midsurfaces: Automatic tool to extract the midsurface of sheet metal stampings, molded plastic parts with ribs, and other parts that have thickness clearly smaller than width and length.

Access
Go to Geometry > Midsurfaces > Automatic.

Options

Destination component
Select which component newly created midsurfaces are placed in.
Mask input geometry
Hide input midsurfaced geometry in the modeling window upon exiting the context.
Extract across components
Extract the midsurface of one component at a time.
Clear existing plates
Clear existing plates prior to midsurface extraction.
Midsurface method
Select a method for midsurfacing.
Planes + Sweeps + Offsets
Identify the places where a piece of plane or a piece of a sweep surface can be used as a middle surface. A middle surface is constructed at the remaining places in the model, for example the places where planar or sweep surface pieces cannot be used as a middle surface, by the same algorithm as in offset via the offset of the model's sides.


Figure 3.
Planes + Offsets
Identify the places in the model where a piece of plane can be used as a middle surface. At the remaining places in the model, for example the places where planar pieces cannot be used as a middle surface, the same algorithm as in Offsets is used to construct the middle surface via the offset of the model's sides.


Figure 4.
Offsets
Create pieces of the middle surface by offsetting the model's side surfaces towards the middle. This is the traditional approach for midsurfacing in HyperWorks.


Figure 5.
Skin Offset
Automatically detects the two largest faces on the model, detects the thickness, and then creates the middle surface by offseting one of the faces towards the other one by half of thickness. This is the quickest method for creating a midsurface. However, it is not applicable to many models.
Assumptions:
  • There are smooth transitions along the faces. Sometimes, certain non-smooth transitions may be handled by increasing the default geometry feature angle.
  • There are no smooth transitions at edges/holes from one face to another one, the transitions should be sharp enough.
  • No ribs are present. There should only be one face(plate) in the input.
  • No variations in thickness are taken into account.
The typical models where "skin offset" can be successfully applied are metal stamped parts.


Figure 6.
Generate plates only
Generates midsurface plates without extracting the actual midsurface. Provides the opportunity to review and edit midsurface plates before taking time to extract the midsurface.
Offset midsurface position
Select a method for positioning midsurfaces when the thickness of thin solids is inconsistent.
Align steps
Select a method for offsetting the midsurface.
User-specified
Change the offset of the midsurface, using a value from 0 to 1, in order to specify the offset from the largest side of the volume.
Use base surfaces
Use base surfaces info for midsurface extraction.
Cleanup tolerance
Select a method for defining the cleanup tolerance.
Maximum R/T ratio
If the maximum R/T ratio (radius/thickness) is greater than this value, then that section of the solid will not be midsurfaced.
Define thickness limits by
Select a method for defining thickness limits.
Thickness ratio
Change the min/max thickness ratio for midsurface extraction. This is the highest acceptable ratio of the thickest plate’s thickness to that of the thinnest plate. Thicknesses above this ratio are ignored.
Minimum thickness
Change the minimum thickness of the plates in the part that should be midsurfaced. Plates with a thickness smaller than this value will not be midsurfaced.
Maximum thickness
Change the maximum thickness of the plates in the part that should be midsurfaced. Plates with a thickness greater than this value will not be midsurfaced.