Exporting Plies

This task shows how to export plies.

  1. Click Export Plies in the Composites Link toolbar.

  2. Select the elements to export:
    • Entire Stacking
    • Selected Groups of plies. Use this option for complex models with multiple surfaces.
      A typical example is a sandwich panel with separate plies groups to define the skin above and below the core.
      The content of the list varies with the environment:
      • In a part environment, groups of plies are listed.
      •  In a product environment, all the parts contained in the product are listed and selectable.
        The ply definitions found in the parts (if any) are exported in the order of the list, from top to bottom.
        Use Move Up and Move Down to modify that order.
        Order matters when surfaces in the CAD model are coincident.

        In this example, we have separated the skin, flange and web for visualization purpose.
        But if the skin, flange and web part surfaces are in the same plane where the core sample cuts through (dotted line),
        there is no automatic way to determine the correct order of the three stacks.
        You need to order them for further use by Composites Link.

    Select the Export Cores check box to include existing cores in the export file.

  3. If necessary, select materials to exclude:
    All the plies referencing the selected materials are excluded from the export.
    This is useful to avoid exporting non-structural plies, such as peel plies, which are of no interest for an analysis.

  4. If necessary, select the Rename check box to activate the renaming of materials.
    This is useful when designers and analysts do not use the same material names
    (mainly because of name length restrictions for materials used in the analysis).
    • Create and store the rename file (spreadsheet stored in CSV - comma-separated variable) format.
      The CATIA name is in column A, while the matching exported name is in column B.

      Use \* as a wildcard for CATIA materials, in any position of the name string.
    • Click ... to select the storage path of the rename file.
      Note that the name of the file appears only if it is valid.
    • Alternatively, use the variable SLTCompositesLinkMaterialRenameFile to set a default storage path.
    • Clear the check box to de-activate the renaming, even is a rename file is selected.

  5. Under Mesh, select how to create the elements on which the ply data are exported.
    These elements can be created by:
    • Tessellation
      The underlying surfaces of the plies cut up using every ply boundary and curves referenced by the producibility parameters,
      and tessellated to create triangular shell elements on which the ply layup is defined.
      This representation reflects the CATIA representation accurately, but is not suitable for the purposes of Finite Element Analysis (FEA).
      In this case, the layup file generated by Composites Link need to be mapped onto a layup model based on an analysis mesh in the analysis environment.
      This can be done with all analysis products using Simulayt Layup Technology,
      such as Composites Modeler for Abaqus/CAE, Composites Modeler for Femap, MSC.Patran Laminate Modeler or Laminate Tools.
      The tessellation is controlled by the Sag Value, or the maximum distance between the tessellation and geometry,
      and optionally, the Step Value which controls the maximum size of the tessellation triangles.
      This option is not available in a product environment. You need to select one of the following options.
    • CATIA Mesh
      This option is available only is a shell mesh for analysis purpose exists in the CATIA model, in a CATAnalysis.
      You can select it when the linked model is activated from within the analysis model
      (Go in the Analysis workbench and double-click the part containing the stacking).
      It is similar to importing a mesh from an external file, except that you select a CATAnalysis instead of a file.
      A mesh created in CATIA has the advantage of respecting the ply boundaries.
    • External Mesh File
      A shell mesh is read from a selected Nastran bulk data file (.bdf or .dat), an Ansys CDB, an Abaqus .inp file (the first  part only)
      or layup file and highlighted in the viewport to make sure it corresponds to the geometry.
      Composites Link first maps the ply layup onto this mesh using CATIA core sampling capability
      before exporting a layup (or Nastran/Ansys) file containing the ply layup.
      This layup file can be imported directly into analysis environments and used without further mapping.
    • CATIA Mesh Selection

  6. When exporting plies from a CATIA part to a layup file, the export file can include points used for stress recovery or as reference points for downstream use.
    Make sure these points are visible, and gathered under a geometrical set named Target Points under the root level.
    They are exported to the point store at the root level of the layup object.

  7. Data can be offset using a rosette as a reference.
    In that case, select the Export Surface Offsets check box.
    The point of the offset definition is the origin of the rosette, and the rosette must lie on the surface.

  8. If required, select the Only tessellate surface under plies check box.

  9. Define how the Fiber Angles of exported plies are computed.
    When Tessellation is selected:
    • The facets of the tessellation are processed as elements for the purposes of export.
      The quality of these elements is not sufficient for FE analysis, but can be mapped onto good quality elements later on.
    • With Regenerated (Actual), a draping simulation is run to calculate the angle on each element,
      irrespective of the solver settings for the ply producibility).
      • For layup, the ply definition is written to the layup file used by other Simulayt tools to repeat the draping algorithm and determine the fiber angle for each element.
      • For other output files, the data is written explicitly as a fiber angle for each element
        (The exact format depends on the export file type).
      • This is a relatively quick computation, where the draping simulation requires the corresponding producibility.
        In case of failure (lack of producibility or processing of cores), the ply is processed with Regenerated (Theoretical) or projected.
    • With Regenerated (Theoretical), the angle is computed from the projection of the reference direction onto each element, rotated by the ply angle.
      The data is always written explicitly to files as an angle per element.
      Note that some third party tools use explicit data in the layup file, as they are unable to run a draping analysis.
    • If one Regenerated option is used, the ply coverage from the CATIA core sample and the ply definition
      in CATIA are used to perform a draping simulation to calculate fiber angles, as is done for surface tessellation.

    When using CATIA Mesh or CATIA Mesh Selection, CATIA performs a core sampling to determine which mesh elements are in each ply (ply coverage).

    • With Core Sample (Theoretical), CATIA performs a rosette transfer to retrieve the fiber angle on each element.
    • With Core Sample (Actual), CATIA runs the producibility solver method set for the ply to determine the fiber angle per element.
    • In both cases, the angles per element are written explicitly.
    • Both options recover the theoretical and the actual fiber angles. The method is a general one, but results in a slower export.

  10. Select the Export File format from the list.
    The format proposed by default is Simulayt Layup file format.
    A shell mesh is defined, on which a ply layup is defined.
    The file can be used by tools using or supporting Simulayt layup technology.
    Other possible formats are described in the following tasks.

  11. Click ... to enter the storage path of the export file.