An Effective Laminate is a Composite Material that approximates the behavior of a Laminate with specified ply materials and percentages. Effective Laminates maintain many of the desirable characteristics of composite laminates, such as the ability to tailor the directional stiffness and strength. However, they do not require an explicit definition of the ply sequence.
Note
Because there is no explicit ply sequence, the analyses of these materials are approximate and are generally not suitable for final design.
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Effective Laminates (EL) are suitable for rapid optimization since they can be Sized by changing their thickness without consideration for their actual layup stacking order. Read more here.
For strength analysis, the Effective Laminate is treated as a pseudo three stack laminate. The middle stack is a smeared orthotropic ply that makes up the majority of the laminate thickness. This ply is used to provide the membrane stiffness.
At the IML and OML of the laminate, there are stress evaluation points. These stress evaluation points are the locations at which the software evaluates the strength margins by resolving the laminate strains into ply strains using very thin plies in each orientation.
Important
The allowables stored for the Effective Laminate, on the Material form, are based on the embedded failure theory (Tsai-Hahn). These allowables are not used to write margins of safety for strength. The ply stress/strain allowables for the source orthotropic ply material are used to evaluate strength margins for the laminate.
Effective Laminates cannot be manually created, they are automatically generated by the software according to user-defined preferences. There are two different mechanisms for initiating this process:
Option #1: From the Ribbon
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Navigate to the Material Tab of the Ribbon.
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Select 'Effective Laminate Generation'.
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Use the resulting form to select the desired Ply Material(s) from those existing in the Database.
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Define the Percentage boundaries and step sizes of each Ply Angle orientation.
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Select 'Generate' to automatically generate all combinations of Effective Laminate materials that fall within the defined Ply Angle Percentage bounds.
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Open the Effective Laminate Library to review the resulting Effective Laminates.
Option #2: From the Design Property Form
This option is only available if: (1) the chosen concept supports a Laminate Material system, and (2) the Sizing Mode is set to 'Detailed Sizing'
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Right-click in the same Material selection box and select 'Generate Effective Laminates...'.
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Select a Tape and/or Fabric Material.
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Define the Percentage boundaries and step sizes of each Ply Angle orientation.
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Select 'Generate' to automatically generate all combinations of Effective Laminate Materials that fall within the defined Ply Angle Percentage bounds.
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The Material box of the Design Property form will automatically be populated with all generated Effective Laminates.
The only defining parameter of an existing Effective Laminate that can be edited is the Ply Angle Percentages. To do so:
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Open the Effective Laminate Library by double-clicking on the 'Effective Laminate' node of the Property Tree.
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Select the Effective Laminate desired for edit.
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Alter the Ply Angle Percentages, then select 'Apply' to save all changes.
Any Effective Laminate can be deleted from the Database using the controls in the Effective Laminate Library.
Important
An Effective Laminate cannot be deleted if it is being referenced by a Design Property. In order to delete an Effective Laminate, it must be completely dissociated from all Design Properties.
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Launch the Effective Laminate Library by double clicking on the Effective Laminate node in the Library of the Property Tree.
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Select all Effective Laminates to delete.
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Choose the 'Delete' option at the bottom of the Library window.