If you are using one of the 3D shell models, you can compute the extension components described in Calculation of the Extensions. The procedure is as follows:
Create a new sub-task.
Create a sub-task
Select Postprocessor as the sub-task type.
Postprocessor
When prompted, enter a name for the postprocessor sub-task.
In the F.E.M. Task Postprocessor menu, select Extension Evaluation (at the bottom of the list).
Extension Evaluation
Ansys Polydata will tell you where the calculation will be performed (the domain of definition of the shell). You can click in the message dialog box to continue.
Specify which extension-related calculations you want to perform. By default, only the area stretch ratio is computed. To enable vector evaluation of the extensions, select the appropriate Enable menu item. To disable any of the currently enabled components, select the corresponding Disable menu item. For cylindrical parisons and preforms as well as initially flat sheets, the initial vector sets can be defined as parallel or perpendicular to a given direction D. In addition, for initially flat sheets, initial vector sets can also be defined along radial and circumferential directions with respect to a given point P.
Specify the reference direction vector and point for the unit vectors described in Calculation of the Extensions (
, and 
).
Modify the reference direction D
Modify the reference point P
Ansys Polyflow will use a geometrical construction to determine the two sets of vectors based on the specified reference point and direction.
When vectors are defined as parallel to a given direction D, the initial vector at a point Q is defined as tangent to the shell in a plane containing Q and parallel to D. When vectors are defined as perpendicular to a given direction D, the initial vector at a point Q is defined as tangent to the shell and perpendicular that direction D.
When vectors are defined as radial around a given point P, the initial vector at a point Q is defined as tangent to the shell in a plane containing points P and Q and perpendicular to the shell. When vectors are defined as circumferential around a given point P, the initial vector at a point Q is defined as tangent to the shell and perpendicular to the radial vector.