# Transforming results into a new coordinate system

 By default, Abaqus/CAE displays element-based field output results in the coordinate systems defined during preprocessing and node-based field output results in the global coordinate system. If you defined nodal transformations during preprocessing, you can choose to apply these transformations to node-based results. Alternatively, you can choose to transform both element- and node-based results into a user-specified coordinate system or to apply an angular transformation to coordinate- and distance-based nodal vector results.
 Related Topics Understanding how results are computed Creating coordinate systems during postprocessing Why are datum coordinate systems so important? Creating field output by operating on fields

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For vector quantities such as displacement, velocity, and acceleration, which are derived from nodal coordinates, Abaqus/CAE transforms the results to the requested coordinate system using the final quantity (saved vector) instead of the original coordinates. For example, the cylindrical displacement component is computed by projecting the displacement vector along the current r- or $θ$- direction. By comparison, taking the differential between the transformed nodal coordinates would yield a different result.

When you transform results into a local coordinate system, Abaqus/CAE rotates the global rectangular coordinate system as needed to align with the local system at the point of interest. The transformed results are reported in the rotated global rectangular coordinates.

For transformations to user-specified coordinate systems, Abaqus/CAE includes the effects of the current deformation by default when deformation effects are available. You can exclude these effects if you want transformation calculations to consider only the undeformed state. Deformation effects are not scaled; Abaqus/CAE performs these calculations using a deformation scale factor of 1.0. Including deformation effects in a transformation can change the orientation of node-based coordinate systems, the projection of coordinate systems on shell and membrane elements, and the orientation of location-dependent cylindrical and location-dependent spherical coordinate systems.

When you select a user-specified coordinate system for a transformation, you can also adjust the display of primary variable results or results from both the primary and deformed variables to account for the rigid body transformation of the coordinate system. Displaying deformations that account for rigid body transformations enables you to visualize the relative displacements of the model with respect to a moving, user-defined coordinate system. For more information about selecting results variables, see Selecting the primary field output variable, and Selecting the deformed field output variable.

You can apply angular transformations for coordinate- and distance-based nodal vector results. The angular transformation computes components in terms of R, $θ$, and Z for cylindrical coordinate systems and in terms of R, $θ$, and $ϕ$ for spherical coordinate systems.

You can apply layup orientation transformations for results that include output from the field output variable SORIENT and include composite sections. This transformation computes tensor and vector fields using the orientation of elements on each individual ply rather than using a single orientation for the entire composite layup.

1. Locate the Transform Type options.

From the main menu bar, select ResultOptions; then click the Transformation tab in the dialog box that appears. The Transform Type options appear.

2. Select the transform type to use for your results.

• Select Default to use the default coordinate systems defined for your model. Node-based results are displayed in the global system. Element-based results are displayed in the local orientations defined for the model; if none have been defined, the global system is used. A projection of the global system or local orientation is used for two-dimensional continuum elements, shell elements, and membrane elements.

• Select Nodal to consider local directions that have been defined at the nodes. Element-based results are displayed in the default coordinate system (as described above). Nodal transformations defined for the model are applied to node-based results; if none have been defined, the global system is used.

• Select User-specified to transform the results for the entire model into a specified coordinate system.

To limit the list for easier selection, type a filter pattern into the Name filter field, and press the Enter key to apply the filter.

Select the transformation to apply from the list of coordinate systems that appears, or click and select the coordinate system from the viewport. Coordinate systems defined either during model generation or during postprocessing are available. Systems designated with an asterisk have been saved to the current output database.

• Select Angular to transform results for coordinate- and distance-based nodal vector results in terms of R, $θ$, and Z or R, $θ$, and $ϕ$. Select the transformation to apply from the list of cylindrical and spherical coordinate systems that appears, or click and select the coordinate system from the viewport. Coordinate systems defined either during model generation or during postprocessing are available. Systems designated with an asterisk have been saved to the current output database.

• Select Layup orientation to transform tensor and vector fields into the layup orientation defined in the composite section definition. Your output database must include the field output variable SORIENT to perform this transformation.

3. If you selected a user-specified coordinate system, you can also include the effects of deformation in the transformation to that coordinate system.

Toggle on Include effects of deformation (when available) to include the effects of deformation, or toggle off this option to exclude the effects of deformation and to consider only the undeformed state in the transformation.

4. If you selected a user-specified coordinate system, you can also apply rigid body transformations to the presentation of primary and deformed variables.

From the Rigid Body Transformations options, do one of the following:

• Toggle on Primary variable to apply rigid body transformations to the primary variable results.

• Toggle on Primary variable and Deformed variable to apply rigid body transformations to the results for both variables.

5. Abaqus displays results in the current viewport in the specified coordinate system or systems. Angular components are given in radians. Angular transformation component results are denoted using (AT: CSYS-name), and rigid body transformation component results are denoted using (RT: CSYS-name) to differentiate them from the results obtained using the default transformation type.

By default, your changes are saved for the duration of the session and will affect all subsequent display of results. If you want to retain your changes for subsequent sessions, save them to a file. For more information, see Saving customizations for use in subsequent sessions.