About Laminates

Below is some information about the role of the laminates and the evolution of their data representation.

The main input for the Composites designers is:

• The reference surface that supports the plies (main 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 resists 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, orientation, and possibly a layer key.
• A thickness law, that only indicates the number of layers for each couple of material/direction used.
• A thickness ratio, that indicates the ratio of each direction/material couple used, and the defined thickness.

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

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

You can define laminates by exporting their definition as an external file, modifying it and reimporting 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
  #
  

Although this is not the recommended way, it is possible to import the laminates from a grid definition file, exported as explained in , as this file contains both information on the grid and on the laminates. However, the information on the grid is not taken into account. In particular, if you re-export the laminates obtained this way from the Composites Parameters dialog box, the information on the grid is lost in the export file.

The command is also different, as it imports laminates information specific to defined zones, given as thickness laws, without color data, whereas Composites Parameters imports full laminates information, with stacking defined either as thickness laws or stacking sequences.