About Materials and Laminates

Before V5R18

• Zones are linked, via the laminate, to materials inside a CATMaterial.
  If the CATMaterial is not available, the zone laminate is KO and the following cannot be created:
  • Plies from zones,
  • Solid/top surface from zones.
• Each ply is linked to a material inside the CATMaterial
  if the CATMaterial is not available, the ply is KO and the following cannot be created:
  • Solid from plies
  • Exploded surfaces
  • Producibility/ Flatten
  • etc.

In short, nothing can be done with a Composites CATPart if the corresponding CATMaterial is not available, which causes numerous issues especially when sending models to a partner for example.

In V5R18 and Above

Starting with V5R18, you can define the Composites Parameters by selecting only the required materials from one or several catalogs, instead of selecting a whole material catalog. This enables the Composites Parameters to store a list of material cache features that will each have:

• a list of knowledgeware parameters corresponding to the material properties needed to update the CATPart even if the material catalog is not available,
• a link to the corresponding material in a material catalog.

Please note:

• Pre-V5R18 models need to be updated.
• You can define a material as NCF.
• Not all material parameters are stored in the Composites Parameters.
  This means that a FEA analysis cannot be performed if the catalog is not available.
• The materials proposed in the commands defining zones and plies are only those defined in the Composites Parameters.
• Instead of having an applied material like in previous releases, the ply will only a point to the corresponding material cache available in the composites parameters.
  You can no longer apply a material at a ply level.
  Replacing a material in all plies will be done through the rerouting of the material link.
• The laminate feature of zones will no longer point to the materials in the CATMaterial like in previous releases.
  It will now directly point to the Composites materials stored under the Composites Parameters. This will be transparent for the user.

About Material in Composites Braiding

Most material catalogues have a fabric width that matches the width of the material when used in a hand lay-up. When working in Composites Braiding, we recommend that you create a material catalogue with the same materials, but with thicknesses and widths that match the tows used by the braiding machine.

As the dialog box is populated with this data when you select a material, it is useful to have a material catalogue that contains sensible default values. The dialog box will list materials with their name and width x thickness

About Laminates

The main input for the Composites designers are:

• The reference surface that supports the plies (master geometry),
• The zone map and stacking table coming from the stress office, resulting from a FEA analysis.

The stacking table (typically given as a spreadsheet) defines the requested laminate for each zone of the reference surface. The laminates ensure that the structure will resist to the expected stress.

A laminate can be given as:

• A stacking sequence, that defines precisely the stacking as an up-down ordered list of layers, characterized by their material and orientation,
• Or as a thickness law, that only indicates the number of layers for each couple of material/direction used.

A thickness law can easily be retrieved from a stacking sequence, whereas several stacking sequences correspond to a same thickness law.

The laminate is dealt with differently by the Grid Approach and the Solid Approach:

• In the Solid Approach, the laminate is explicitly implemented as a feature visible in the specification tree, under each zone. The laminate is defined for a given zone, and can only be edited as a thickness law: for one or several materials, the number of layers is given for each possible orientation. Designers can select an existing laminate in the specification tree and fill in the thickness law directly from it.
• In the Grid Approach, the laminate is not explicitly implemented as a feature, and is not visible in the specification tree. For each cell of the grid, the laminate can be defined as a stacking sequence, or as a thickness law. Two laminates can be defined: the reference one, and a modified one. Laminates can be defined globally for all the cells by importing/exporting a grid definition file, and stacking can be propagated to several cells.

In V5-6R2013 and Above

Laminates have been enhanced to extended laminates:

• Extended laminates can be defined at the start of the design, using the Composites Parameters command, or later, while editing grids or zones.
  • The extended laminates can be explicitly defined either as a stacking sequence or a thickness law, using the Composites Parameters command, in both Grid Approach and Solid Approach.
    Definition as a stacking sequence is possible in Solid Approach, for compliance reasons. However, the laminate is considered as defined by a thickness law, meaning the material is defined for a given zone and edited only as a thickness law.
  • They can also be implicitly defined when importing grid data from external data or from a virtual stacking: extended laminates are created if existing ones do not cover the needs, i.e. if the stacking used for a cell does not correspond to an existing extended laminate.
  • Both Excel and text file formats are supported to define the laminates through import/export capabilities.
  • New laminates can be created on the fly, without exiting the grid cell or zone definition commands. They will be visible under Composites Parameters.
  • Automatic creation of extended laminates with grid cell or zone definition commands can be de-activated, to ensure that only validated extended laminates are used (e.g. to ensure compliancy with in-house rules).
  • Information is displayed when extended laminates have been created after an import, or when automatic creation is disabled and missing laminates are found.
• The list of laminates is visible at a glance under the Composites Parameters node in the specification tree.
• Existing laminates are easy to re-use.
• Laminates can be renamed to meet a company standards.
• A color is associated to each laminate for a more stable 3D visualization.
• Each cell of a grid (Grid Approach), or zone (Solid Approach) points to an extended laminate to define its local stacking. A grid cell can point to two extended laminates (reference and modified).

An automatic migration to extended laminates is started when you open an old model, that creates a laminate object for each stacking/laminate found in grids and zones.

About Master Stacking Sequence

You can import a spreadsheet defining a Master Stacking Sequence and all associated laminates to be used in a model (one laminate per column). It looks like follows:

• A Master Stacking Sequence (first two columns), which is an ordered list of layers, defined by a material and an orientation (as shown in the red squares below) and a layer level and a layer name (optional, can be left blank). Once generated, the Master Stacking Sequence can be used to create the virtual stacking.
  Example of layer with layer level and layer name:
  
• Stacking sequence laminates (following columns) linked to the Master Stacking Sequence as shown below, where:
  • The Master Stacking Sequence is on the left, the stacking sequence laminate is on the right.
  • The first column lists the materials while the second lists the directions.
    
  • Optionally, the second line of the spreadsheet can contain a color index for each laminate. All color indices, if any, must be unique. In that case, the format of the file changes slightly.
    

    Material	Orientation	Laminate.2	Laminate.3	Laminate.4	Laminate.5	Laminate.6
    	ColorIds	16	17	18	19	20
    Unidir Material	0	0	0	0	0	0
    Unidir Material	45	45	45	45	45	45
    Unidir Material	90	90	90	90	90	90
    Unidir Material	-45	-45	-45	-45	-45	-45
    Unidir Material	0	0	0
    Unidir Material	45	45	45
    Unidir Material	0	0		0
    Unidir Material	-45	-45		-45
    Unidir Material	90	90		90
    Unidir Material	-45		-45
    Unidir Material	0		0
    Unidir Material	45	45
    Unidir Material	0		0
    Unidir Material	45	45	45	45	45

  • Material ID and orientations must correspond to those existing in the model.
  • All orientations must be the same on a given line and one orientation must be set for each line.

Master Stacking Sequence and Composites Parameters

• If defined for one line, the layer name must be defined for all, and be unique.
• If defined for one line, layer level must be defined for all and be a numerical value.
• Material ID and orientations must correspond to those existing in the model.
• All orientations must be the same on a given line and one orientation must be set for each line.
• All color indices, if any, must be unique.
• Laminates in the model are not deleted if not present in the imported file.
• Imported laminates are displayed in the Laminates tab and marked SS-MSS.
• Laminates previously defined from a Master Stacking Sequence, that have become incompatible with the newly imported Master Stacking Sequence, are turned into standard stacking sequences. A warning is displayed.
• If a virtual stacking had been created from a Master Stacking Sequence and has become incompatible with the newly imported master sequence, a warning is displayed and the link to the Master Stacking Sequence is lost.
• Existing laminates are updated with the information of imported laminates with the same name.
• Each laminate receives a color index, the one contained in the import file if it exists, an automatic one otherwise.

If you re-import a Master Stacking Sequence, the current Master Stacking Sequence and its associated laminate are updated.

• When an existing laminate corresponds to a re-imported one, it is updated.
• When an existing laminate does not correspond to any re-imported one, its compatibility is checked.
  If it is compatible, it remains associated to the Master Stacking Sequence, otherwise, it is changed into a standard Stacking Sequence.
• A laminate is compatible with a new Master Stacking Sequence if its layers are an ordered sub-set of all layers of the Master Stacking Sequence.
• When an existing laminate corresponds to a re-imported one, it is updated at re-import (change of layer level or sequence name).
• Swap of laminates, deletion of a laminate, change of a material or orientation of a layer are not supported.

Master Stacking Sequence and Grid Definition

• When these Stacking Sequences are used in Grid Definition, the virtual stacking is created from the order of layers in the Master Stacking Sequence.
  When defined, the layer lever and layer name provide respectively the level data and sequence name of the generated virtual sequence in the Virtual Stacking.
• Layer information (level and name) is applied to each virtual sequence of the Virtual Stacking.
• Layer levels are stored on each virtual sequence.
• In the Ply entity level view, the layer level is identical for each ply of the same sequence.
• Information display in Virtual Stacking is adapted to the Master Stacking Sequence information.
• At ply generation, layer levels can be used as drop-off order, enabling you to drive the staggering from layer levels defined externally.

Definition via Export/Import

You can define laminates by exporting their definition as an external file, modifying it and re-importing it.
Both Excel and text files are supported.

Example of definition:

Name           TL.1
ColorIdx                    1
Type           TL
Stacking                   0   45   -45   90
U174_T800               18  6     6     4
#
Name SS.1
ColorIdx                   2
Type SS
Stacking
U174_T800              0
U174_T800              45
U174_T800              45
U174_T800              45
U174_T800              -45
U174_T800              -45
U174_T800              -45
U174_T800              90
U174_T800              90
U174_T800              -45
U174_T800              -45
U174_T800              -45
U174_T800              45
U174_T800              45
U174_T800              45
U174_T800              0
#
Name        TL.2
ColorIdx                  3
Type TL
Stacking                 0   45   -45   90
U174_T800             20  6     6     4
#