Creating continuum shell composite layups

You can define a continuum shell composite layup with a specified stacking direction that is composed of plies made of one or more materials. For each ply of the layup, you specify the name, material, relative thickness, orientation, and the number of integration points. In addition, you select the region to which the ply is assigned. For more information, see Defining a composite shell section.

  1. From the main menu bar, select CompositeCreate.

    A Create Composite Layup dialog box appears.

    Tip: You can also click Create in the Composite Layup Manager or select the create composite layup tool in the Property module toolbox.

  2. Enter a composite layup name. Abaqus/CAE displays this name in a ply stack plot. For more information on naming objects, see Using basic dialog box components.

  3. Specify the initial ply count. When the composite layup editor appears, it will contain a row for each ply; however, you can use the editor to subsequently add or delete plies.

  4. Select Continuum Shell as the Element Type, and click Continue.

    The composite layup editor appears.

  5. Enter a description of the layup. Abaqus/CAE displays this description in the composite layup manager.

  6. Do one of the following to specify the layup orientation:

    • Select Part global to use the part's coordinate system, and choose the axis that represents the Normal direction.

    • Select Coordinate system to select an existing coordinate system (or create a new coordinate system and select it), and do the following:

      1. Choose the axis that represents the Normal direction.

      2. Specify an additional rotation. The selected coordinate system is rotated through this angle about the selected axis. You can specify an angle, or you can select an existing scalar discrete field that defines an angle that is varying spatially across the layup. Abaqus/CAE allows you to select only valid discrete fields, which, for an additional rotation, are scalar discrete fields applied to elements. You can also create a new discrete field by clicking . For more information, see The Discrete Field toolset.”

    • Select Discrete to define a discrete orientation, and do the following:

      1. Click .

      2. In the Edit Discrete Orientation dialog box that appears, define the normal axis and primary axis using the procedure described in Using discrete orientations for material orientations and composite layup orientations.

      3. Choose the axis that represents the Normal direction.

      4. Specify an additional rotation. The orientation is rotated through this angle about the selected normal axis. You can specify an angle, or you can select or create a scalar discrete field that defines an angle that is varying spatially across the layup. Abaqus/CAE allows you to select only valid discrete fields, which, for an additional rotation, are scalar discrete fields applied to elements. You can also create a new discrete field by clicking . For more information, see The Discrete Field toolset.”

    • Select User-defined to define the orientation in user subroutine ORIENT. This option is valid only for Abaqus/Standard analyses. See the following sections for more information:

    • Select the name of an orientation discrete field to specify a coordinate system that is varying spatially across the layup. You can also create a new discrete field by clicking to the right of the Definition field. For more information, see The Discrete Field toolset.” After selecting the discrete field, you must do the following:

      1. Choose the axis that represents the Normal direction.

      2. Specify an additional rotation. The selected coordinate system is rotated through this angle about the selected axis. You can specify an angle, or you can select or create a scalar discrete field that defines an angle that is varying spatially across the layup.

    The layup orientation is the reference orientation for any ply that uses the default orientation system (indicated by <Layup> in the CSYS column of the ply table). This orientation will be used for material calculations and stress output in the individual plies, for the section forces output, and for the transverse shear stiffness. You can specify a different orientation for the individual plies of a continuum shell composite layup by specifying a reference orientation and/or a rotation angle. For more information, see Understanding composite layups and orientations.

  7. Choose one of the following to specify the stacking direction of the continuum shell elements:

    • Element direction 1

    • Element direction 2

    • Element direction 3

    • Layup orientation. The stacking direction is the normal to the layup orientation.

    You can use the Query toolset to determine the mesh stack orientation. However, the displayed orientations account for only the sweep path; they do not account for changes to the stacking direction as described above. For more information on the Query toolset, see Using the Query toolset to query the model. For more information on mesh stack directions, see Defining the stacking and thickness direction.

  8. Choose one of the following Section integration methods:

    • Choose During analysis to specify properties for a continuum shell composite layup integrated during the analysis.

    • Choose Before analysis to specify properties for a pre-integrated continuum shell composite layup.

  9. If you are specifying properties for a composite layup integrated before the analysis, specify the Idealization to apply to the shell based on assumptions about the expected behavior or makeup of the layup. For more information, see Idealizing the section response.

    • Select No idealization to account for the complete stiffness of the shell as determined by the material assignments and ply composition.

    • Select Smeared properties if you do not know the exact stacking sequence for the plies in the composite layup. Contributions from each specified ply are smeared across the entire thickness of the layup, resulting in a general response independent of the stacking sequence.

    • Select Membrane only if the predominant response of the shell will be in-plane stretching; bending stiffness terms are eliminated from the shell stiffness calculations.

    • Select Bending only if the predominant response of the shell will be pure bending; membrane stiffness terms are eliminated from the shell stiffness calculations.

  10. If you are specifying properties for a composite layup integrated during the analysis, select the Thickness integration rule.

    • Choose Simpson to use Simpson's rule for the shell section integration.

    • Choose Gauss to use Gauss quadrature for the shell section integration.

    See Defining the shell section integration, for more information.

  11. When you have finished defining the continuum shell composite layup, click OK to save your changes and to close the editor.