Assigning a material orientation

The global coordinate system determines the default material orientations. However, you can assign specific material orientations to a shell, solid part, region, skin, or stringer by selecting a datum coordinate system or discrete field or by defining a discrete orientation. For an Abaqus/Standard analysis you can define the local coordinate system in user subroutine ORIENT. The datum coordinate systems can be rectangular, cylindrical, or spherical; and you can apply an additional rotation to the coordinate system if required. For more information, see Orientations.

Related Topics
Creating and editing sections
Selecting objects within the viewport
Plotting material orientations
The Discrete Field toolset
Controlling datum display
In Other Guides
Solid (continuum) elements
About shell elements

Context:

In cases where Abaqus/CAE attempts to draw coordinate systems for material orientations at singularity points of the system (i.e., points for which the user-selected coordinate system and the geometric normal from either geometry or elements cannot be resolved into a valid orientation for display purposes in Abaqus/CAE), the coordinate system will be drawn collapsed.

For continuum shell elements, Abaqus/CAE does not project the displayed material orientations onto the midplane surface. You can perform a data check and view the output database in the Visualization module to verify the material orientations. For more information, see Performing a data check on a model.

The material orientations that you assign to a part or region are assigned automatically to all instances of that part in the assembly. You can use the Query toolset to verify that you have assigned the correct material orientation to a selected region. For more information, see Using the Query toolset to obtain assignment information.

You can edit, suppress, and resume previously defined material orientations by clicking mouse button 3 on the material orientation in the Model Tree and selecting the suppress or resume option from the list that appears. For more information, see Suppressing and resuming objects.

  1. If the part to which you want to assign a material orientation is not visible in the current viewport, click the name of the desired part in the Part list located in the context bar.

    The selected part appears in the current viewport.

  2. From the main menu bar, select AssignMaterial Orientation.

    Tip: You can also click the tool in the Property module toolbox.

  3. Select the shell or solid regions from the viewport, and click mouse button 2 to indicate you have finished selecting. (For more information, see Selecting objects within the viewport.”)

    Tip: You can limit the types of objects that you can select in the viewport by using the tools in the Selection toolbar. See Using the selection options, for more information.

    If you select Skins as the object type, you can assign the material orientation to the entire skin or to one or more of its faces. From the prompt area, select (pick entire skin) or (pick partial skin), then make your selection in the viewport. If the selected part has multiple skins, Abaqus/CAE will display the ambiguous picking options in the prompt area while you make your selection.

    If you select Stringers as the object type, you can assign the material orientation to the entire stringer or to one or more of its edges. From the prompt area, select (pick entire stringer) or (pick partial stringer), then make your selection in the viewport. If the selected part has multiple stringers, Abaqus/CAE will display the ambiguous picking options in the prompt area while you make your selection.

    If you would rather select from a list of existing sets, do the following:

    1. Click Sets on the right side of the prompt area.

      Abaqus/CAE displays the Region Selection dialog box containing a list of available part sets. Part sets containing only shells or solids appear in the list.

    2. Select the part set of interest, and click Continue.

    Note:

    The default selection method is based on the selection method you most recently employed. To revert to the other method, click Select in Viewport or Sets on the right side of the prompt area.

  4. If you want to specify a material orientation using an existing datum coordinate system, do the following:

    1. Select the datum coordinate system.

      • Select a coordinate system in the viewport.

      • Select a datum coordinate system by name. Click Datum CSYS List from the prompt area, select a name from the list, and click OK.

      Abaqus/CAE displays the resulting material orientation specified for the region, and the Edit Material Orientation dialog box appears.

    2. Choose Axis 1, Axis 2, or Axis 3 to specify the coordinate system axis.

      • For a shell region, specify the coordinate system axis that approximates the normal to the shell in the Normal Direction portion of the dialog box.

      • For a solid region, specify the coordinate system axis about which an optional additional rotation occurs in the Additional Rotation Direction portion of the dialog box.

    3. If desired, you can provide an additional rotation of the material orientation about the shell normal (for a shell region) or about a local axis of the datum coordinate system (for a solid region) using one of the following methods:

      • Choose Angle, and enter a value in degrees for the additional rotation.

      • Choose Distribution, and select an existing scalar discrete field that defines an angle that is spatially varying across the region. Alternatively, you can click to create a new discrete field. (See The Discrete Field toolset,” for more information.)

      Abaqus/CAE applies the additional rotation, if any, and displays the resulting material orientation applied to the region.

  5. If you want to use the global coordinate system (default) or specify a material orientation in a discrete orientation, user subroutine, or a discrete field, click Use Default Orientation or Other Method from the prompt area. You can also select an existing datum coordinate system or create a new one using this procedure.

    1. In the Edit Material Orientation dialog box that appears, click the arrow to the right of the Definition field, and select one of the following:

      • Select Coordinate system, and click to select a coordinate system from the viewport or by name. Alternatively, you can click to create a new datum coordinate system.

      • Select Global to use the global coordinate system or to reset a previously assigned material orientation back to the global coordinate system.

      • Select Discrete, and click to define a discrete orientation. 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.

      • 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 a discrete field to define a spatially varying orientation. Alternatively, you can click to the right of the Definition field to create a new discrete field. (See The Discrete Field toolset,” for more information.)

    2. Choose Axis 1, Axis 2, or Axis 3 to specify the coordinate system axis.

      • For a shell region, specify the coordinate system axis that approximates the normal to the shell in the Normal Direction portion of the dialog box.

      • For a solid region, specify the coordinate system axis about which an optional additional rotation occurs in the Additional Rotation Direction portion of the dialog box.

    3. If desired, you can provide an additional rotation of the material orientation about the shell normal (for a shell region) or about a local axis of the datum coordinate system (for a solid region) using one of the following methods:

      • Choose Angle, and enter a value in degrees for the additional rotation.

      • Choose Distribution, and select an existing scalar discrete field that defines an angle that is spatially varying across the region. Alternatively, you can click to create a new discrete field. (See The Discrete Field toolset,” for more information.)

      Abaqus/CAE applies the additional rotation, if any, and displays the resulting material orientation applied to the region.

    4. Choose one of the following to specify the stacking direction of continuum shell elements or solid elements:

      • Element isoparametric direction 1

      • Element isoparametric direction 2

      • Element isoparametric direction 3 (bottom to top)

      • Normal direction of material orientation (Continuum Shells only). The stacking direction is the 3-direction of the material orientation.

      If the selected regions are meshed, Abaqus/CAE displays the material stacking direction for each element.

  6. Click OK in the dialog box.