About Envelope Data

Defining envelope data is a convenient way to designate an acceptable range for data collection when subsequently creating contour plots, isocontour plots, and symbol plots. The data range established in the envelope data is then used as input when defining these plots.

You can use envelope data to display minimum, maximum, and absolute maximum values across steps, frames, modes, or load cases. Envelope data can be created for raw data or composite models. For composites, you can apply envelope data over all plies or on individual plies and section points.

This page discusses:

See Also
Defining Envelope Data

Envelope Definition

You define envelopes in the Envelope dialog box, selecting steps, frames, modes, load cases, variables and, in the case of composite models, plies and section points.

You can create one or more envelopes for later use in plot creation. Once created, the envelope names appear in the Feature Manager and in the tree. The Envelope tab of the Feature Manager displays:

  • Envelope Name: Name of the envelope feature.
  • Variables: Specific variables from which the envelope was created (for example, AT, PE, S, U, V).
  • Mode: Mode chosen to define the envelope (Absolute Maximum, Maximum, or Minimum).
  • Support: The support on which envelope data is computed.

The tree displays an Envelope container that expands to show all available envelopes. Each envelope container, in turn, displays the variables used within that envelope.

You can edit envelope definitions from context menus in the Feature Manager or in the tree. When editing the parent envelope, all envelope variables appear in collapsed mode in the Envelope dialog box. When editing an individual variable, you can edit only parameters for that particular variable. You must reselect all other variables and global parameters separately.

Plot Creation Using Envelope Data

Once you have defined the envelope data, it is available from the Feature Manager, the tree, and the Create Plot dialog box. This data can be used for creating contour plots, isocontour plots, and symbol plots, depending on the variable type selected.

To create a plot immediately from envelope data, you can select Create Plot from the contextual menu on the envelope object in the tree or Feature Manager. Alternatively, you can open the Create Plot dialog box first and select the envelope from there.

For contour and isocontour plots, envelope data is available only for the Element type variable. For symbol plots, envelope data is available for both Element and Node type variables as shown in the following table:

Plot type Variable type
Node Element
Contour No Yes
Symbol Yes Yes
Isocontour No Yes

When you create a contour plot, isocontour plot, or symbol plot, you can select an envelope from the Envelope list in the Create Plot dialog box. Selecting an envelope updates the Create Plot dialog box to include only those variables that you used to define the envelope, and the results display data only for the range defined in the envelope. Alternatively, you can create a plot with the envelope definition of your choice by selecting Create Plot from the envelope object in the tree or from the envelope object in Feature Manager.

Note: When you create a plot using envelope data, the step and frame information used is within the constraints of the envelope, regardless of the Quantity you select in the Create Plot dialog box. For example, if you create an envelope with the Stress variable and Tensor Component 11 (S11) quantity, and maximum stress occurs at step 1, frame 2, and if you then create a contour plot of S12, the displayed contour plot uses step 1, frame 2, to fit the range defined in the envelope, even if the maximum for S12 occurs in a different frame. (The envelope constraints take precedence in the plot display.)

The Envelopes container in the tree displays the plot information associated with the envelope. After you have created a plot using envelope data, selecting a step in the Plots dialog box does not change the displayed plot or the legend. The only changes initiated from a plot dialog that are immediately visible while using envelope data are changes to the deformation.