HyperView User's Guide

Iso Panel

Iso Panel

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Iso Panel

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The Iso panel allows you to display single iso values (iso surfaced for solids or iso line for shells) dependent on results data.  The result data used to calculate the iso surfaces or values can be specified independently of the result data selected in the Contour panel, even though most of result selection options are similar to the contour options.  Since an iso value is independent of contour results, for OptiStruct design space optimization results, you can apply a single iso surface for density, then contour stress results on the generated iso surface.  Combining contour, iso value, and transparent global boundary geometry (shortcut key "T") is an excellent way to investigate hot spots of result data.  By varying the iso value slider bar, you can easily observe critical areas.

To access the Iso panel, click Iso resultsIso-24 on the Results toolbar, or select Plot > Iso from the Results menu.

iso_value_panel

Iso panel

The following options are applied to the model when you click Apply.

Result type

This section allows you to select the name of the result data type that should be used to calculate the contours.  Use the drop-down list under Result type to make your selection.  The available result types change depending on the result file that is loaded.

Each result type is followed by a letter that indicates the category to which it belongs.  (t) indicates a tensor-type result, such as stress or strain tensors.  (v) indicates a vector-type result, such as displacement, velocity, and acceleration.  (s) indicates a scalar-type result.  (c) indicates complex results.

Click the expansion button, exp-button, to open the Choose From List dialog where you can filter result types for faster selection.

choose_from_list_dialog

The second drop-down menu in the result type section allows you to choose the data component type.  The list of available components is based on the selected result type.  For example:

 

Result type

Component options


Displacement (v)

Mag, X, Y, or Z.


Stress (t)

vonMises, Signed vonMises, P1(major), P2(mid), P3(minor), Pressure, MaxShear, Intensity, In-plane P1(major), In-plane P2(minor), XX, YY, ZZ, XY, YZ, or ZX.


1D stress

Multiple options are listed for various elements such as: CELAS, CROD, CBAR, CBEAM, etc.


Energy (s)

No component selection is necessary.

Layers

Allows you to create an iso surface for a specified element layer when a layer definition is available for an element.  The settings are applied to all layers defined in the model. If an element has no layer definition, as with solids, the iso surfaces are displayed regardless of layer selection. The options are:

 

Max

Displays the maximum value among the layers for each entity.

 

Min

Displays the minimum value among the layers for each entity.

 

Extreme

Displays the maximum absolute values among the layers for each entity.

 

Sum

Displays the (scalar) sum of all values among the layers for each entity.

 

Average

Displays the (scalar) average value among the layers which contain data for each entity.

Layers that do not have values (N/A result) will not contribute to the averages (see the example below):

Layer 1 - 10.0
Layer 2 - 26.0
Layer 3 -  30.0

Average is (10+26+30)/3 = 66/3 = 22.0

However if:

Layer 1 - 10.0
Layer 2 - 26.0
Layer 3 - N/A

Average is (10+26)/2 = 36/2 = 18.0

 

Range

Displays the difference between the maximum and minimum values among the layers for each entity.

 

Count

Displays a count of the layers for the given data type.  By default, the total number of layers/plies are given for each node/element.  When used with a Layer Filter or Value Filter, the Count aggregation mode will have slightly different behavior (based on the filter criteria).

 

MaxLayer

Plots an iso-surface based on the available layer index that contributes to the maximum value for each entity.

 

MinLayer

Plots an iso-surface based on the available layer index that contributes to the minimum value for each entity.

 

ExtremeLayer

Plots an iso-surface based on the available layer index that contributes to the extreme (absolute maximum) value for each entity.

 

Note (for layers):  Only in the case of results based at the elemental centroid, would one layer per element be displayed.  For corner bound or nodal bound results (in the case of averaging), different layers may contribute to the max/min/extreme value at each corner/node of the same element.

When plotting an iso-surface for MaxLayer, MinLayer, or ExtremeLayer, a layer index which may be specific to the file is used.  This index does not provide you with any useful information, therefore the iso-surface plot by itself will not be effective without an accompanying contour plot. In addition, the Current Value or the Slider for changing the iso-surface values is not recommended when using MaxLayer/MinLayer/ExtremeLayer.

Click here to view a table in the Derived Load Steps topic which explains the behavior of layer aggregation (Min/Max/Range) in combination with the Min/Max/Range Envelope loadstep types.


Solver specific
layer options

Solver dependent label(s).  For example, Z1 and Z2 would indicate the lower and upper layers of shells in a Nastran model.


Layer Filter layer_filter_icon

Reduce the layer list available for aggregation for the data types which have layers (for example, plies in composite stress/stains or any vector result with layers).

Use corner data

If corner data is available, the Use corner data option is enabled. This option will display color bands by interpolating available corner results within each element.  A discontinuity of the result distribution across element boundaries can be seen.

Selection

Before creating an iso plot, you may pick one or more entities from the model.  You can do this by picking entities directly from the screen, using the quick window selection, or clicking the Components input collector and using the extended entity selection menu.  If no selection is made, the iso plot will be applied to displayed components by default.  See Selecting Entities Using the Input Collector for more information on selecting entities.  For iso or multiple models see MultiModel Result Plotting for additional information.

Component selection restricts the iso surface to the selected parts only, while displaying the rest of the geometry which needs to be displayed in full.  In most of the CFD applications, the fluid elements need to be iso surfaced, with the structural parts displayed as a whole. The figure below shows a pump impeller geometry, with the iso surface on the fluid elements based on pressure data.  The contour shown is velocity of the fluid as it is displaced by the impeller blade.

iso_panel_selection_example_hv

When performing ALE simulations in RADIOSS, or other solvers, of fuel tank sloshing or ditching of an airplane, the iso surface of density on selected components (the mesh representing the fluid) helps visualize the interaction of the fluid with the structure.  The image below shows a ditching simulation of an airplane in water.  The airplane block is investigated while the density iso surface is applied only on the fluid to show the water displacement due to ditching.

iso_panel_selection_example2_hv

Resolved in

Select the result coordinate system that will be used to contour the results.  You can select the analysis, element, or global system as well as a user-defined system.  The System input collector is enabled when User System is selected.


Global System

Transforms to the global system.

proj: none indicates that no projection rule is selected for shells.  If a projection rule is selected (using the Projection Rule button) it will be displayed.


Elemental System

Transforms results to the element coordinate system.  In HyperView, the element coordinate system is defined by element connectivity.


Material System

Transforms to the material system.

This option is only available when the Advanced Result Math template is selected in the Load Model panel and a solver input deck is loaded.

For plotting data types that do not have relevance to the Material system (for example, Stress with a Z1 and a Z2 data type), it is not advised that you apply the Resolved-In system of Material, because this may result in incorrect transformations.


Ply System

Transforms to the ply system.

This option is only available when the Advanced Result Math template is selected in the Load Model panel and a solver input deck is loaded.

For plotting data types that do not have relevance to the Ply system (for example, Stress with a Z1 and a Z2 data type), it is not advised that you apply the Resolved-In system of Ply, because this may result in incorrect transformations.


Analysis System

Displays the vector and tensor results as they are output from the solver.


User System

This option is available when the results file contains a user-defined coordinate system. Click the System input collector to select a system by ID or pick from the screen.

proj: none indicates that no projection rule is selected for shells.  If a projection rule is selected in the Projection Rule dialog, it will be displayed next to the User System option.

Use tracking
system

If a tracking system has been activated in the Tracking panel, the Use tracking system option is enabled.  If you activate this option, the results will be transformed and resolved in the activated tracking system.

This option is not available if you are using the Modal or Linear Static animation mode.

Show midside node results

If the checkbox is checked, HyperView will calculate or use mid-side node results when displaying an iso plot.

This option is disabled whenever any of the following conditions are met:

Loaded results do not have 2nd order elements.
Results are on nodes, components, or systems.
Averaging mode is set to Max/Min/Extreme of corner.
Use corner data option is off and the averaging mode is set to None.

Use Contour
Settings

If you prefer to use the settings from the previously applied results in the Contour panel, click Contour Settings to apply them here.  The Contour Settings option changes the settings on the Iso Value panel to match the settings on the Contour panel (including the Value Filter settings).

Projection Rule

This button (on the far right side of the panel) opens the Projection Rule dialog where you can select the primary and secondary axes from either the global or user-defined system (selected for Resolved in).  When the primary axis is perpendicular to the shell plane, the secondary axis is used.

projection_rule_dialog

Averaging
method

None

When elemental centroidal results are used, None is not available in the Iso panel since node based results are required to generate an iso value.  So, if you apply elemental centroidal results, you need to select one of the averaging methods.

If nodal results are used, no selection of averaging methods is possible.


Simple

Tensor and vector components are extracted and the invariants are computed prior to averaging.


Maximum

Extracts the maximum values from the surrounding elements attached to a node.  The tensor and vector components are extracted and the invariants are computed for each element (or corner) prior to averaging to a node.  For results components, the corresponding components from each element corner (or centroid) are extracted and then the maximum value is assigned to the shared node.  For invariants, the corresponding invariants are calculated from each tensor at the element corners and then the maximum value is assigned to the node.

For example, as shown in Nodal Averaging of Elemental Results, there are four tensors, [A2], [B1], [C3], and [D4] at four corners at Node 400.

The maximum average of the xx component at Node 400 is:

max_averaging_formula1


Minimum

Extracts the minimum values from the surrounding elements attached to a node.  The tensor and vector components are extracted and the invariants are computed for each element (or corner) prior to averaging to a node.  For results components, the corresponding components from each element corner (or centroid) are extracted and then the minimum value is assigned to the shared node.  For invariants, the corresponding invariants are calculated from each tensor at the element corners and then the minimum value is assigned to the node.

For example, as shown in Nodal Averaging of Elemental Results, there are four tensors, [A2], [B1], [C3], and [D4] at four corners at Node 400.

The minimum average of the xx component at Node 400 is:

min_averaging_formula1


Advanced

Tensor (or vector) results are transformed into a consistent system and then each component is averaged separately to obtain an average tensor (or vector). The invariants are calculated from this average tensor.


Difference

The difference between the maximum and minimum corner results at a node.


Max of corner

Extracts the maximum value from all the corners of an element and the value is shown at the centroid of the element.  The tensor and vector components are extracted and the invariants are computed for each corner prior to assigning to the element centroid.  For result components, the corresponding components from each corner is extracted and then the maximum value is assigned to the element centroid.  For invariants, the corresponding invariants are calculated from each tensor at the element corners and then the maximum value is assigned at the centroid.

For example, as shown in Nodal Averaging of Elemental Results, there are four tensors at each corner of the element A:  [A1], [A2], [A3], and [A4].

The max of corner aggregation of the xx component at the Element A centroid is:

max_of_corner_avg_formula_hv

This averaging option is only available when the Use corner data option is checked.  The Variation option is automatically disabled for this averaging method.


Min of corner

Extracts the minimum value from all the corners of an element and the value is shown at the centroid of the element.  The tensor and vector components are extracted and the invariants are computed for each corner prior to assigning to the element centroid.  For result components, the corresponding components from each corner is extracted and then the minimum value is assigned to the element centroid.  For invariants, the corresponding invariants are calculated from each tensor at the element corners and then the minimum value is assigned at the centroid.

For example, as shown in Nodal Averaging of Elemental Results, there are four tensors at each corner of the element A:  [A1], [A2], [A3], and [A4].

The min of corner aggregation of the xx component at the Element A centroid is:

min_of_corner_avg_formula_hv

This averaging option is only available when the Use corner data option is checked.  The Variation option is automatically disabled for this averaging method.


Extreme of corner

Extracts the extreme value from all the corners of an element and the value is shown at the centroid of the element.  The tensor and vector components are extracted and the invariants are computed for each corner prior to assigning to the element centroid.  For result components, the corresponding components from each corner is extracted and then the extreme value is assigned to the element centroid.  For invariants, the corresponding invariants are calculated from each tensor at the element corners and then the extreme value is assigned at the centroid.

For example, as shown in Nodal Averaging of Elemental Results, there are four tensors at each corner of the element A:  [A1], [A2], [A3], and [A4].

The extreme of corner aggregation of the xx component at Element A centroid is:

extreme_of_corner_avg_formula_hv

This averaging option is only available when the Use corner data option is checked.  The Variation option is automatically disabled for this averaging method.


Variation (%)

The relative difference at a node from corresponding corner values with respect to the value range from all nodes in the selected components.

If the variation in the results is smaller than the specified percentage, HyperView will average the corner results to the nodes.  If the variation is larger than the specified percentage, HyperView will keep the discontinuity of the results.

This option is not available for all averaging methods.

Averaging
options

The averaging options allow you to limit the averaging of results to only a group of elements that are considered to be bound by same feature angle or face.

Typically averaging is performed for all connected elements in a part without any regard for adjacent elements that are modeled around sharp edges or T-connections

Click Averaging Options (located in the middle of the panel) to display the Averaging Options dialog.

averaging_options_dialog_hv

Note:  Feature angle averaging is only applicable when the Simple or Advanced averaging methods are used, and no Variation is selected.  As the nodes shared by elements that do not meet the feature angle criteria can have different values on either side of the feature angle, the output is always presented as corner bound values on each element.

 

Average across component boundary

Enables the nodal averaging across the component boundary.  The contribution for a shared node will come from every component associated with that node, while all of the other averaging principles remain.

 

Feature angle
averaging

Activate this option to specify the threshold value for elements to be considered as part of the same feature by specifying a Feature angle value.  All of the adjacent elements whose normals are less than or equal to the threshold value are averaged.

The output of this contour is always corner based data (no centroid values).  A feature angle average calculation example is shown below:

feature_angle_avg_example_hv

Result at common node 3440:

E 3115, average of corner nodes for element 3115 and 3117
E 3121, average of corner nodes for element 3121 and 3124
E 3117, average of corner nodes for element 3115 and 3117
E 3124, average of corner nodes for element 3121 and 3124

 

Feature angle

Allows you to specify the value to be used in the Feature angle averaging calculations.  The default is 30 degrees.  All of the elements whose normals are less or equal to the specified threshold value are averaged.  The value can range from 0 to 180 degrees.

For element feature angle calculation, the current model position is used.  Only shell elements feature angles are considered, therefore all solid and beam elements will be included in the averaging calculation (see the example below):

feature_angle_avg_example2_hv

The result at common node 20983 = the average of corner nodes for all four elements.

 

Ignore flipped
normals

This option is checked by default (for feature based averaging) to allow for any modeling discrepancies to be disregarded.

Consider the picture and description below which shows two adjacent elements whose normals are flipped as a consequence of a model setup discrepancy:

averaging_options_diagram_hv

In the example above, the feature angle threshold for averaging is set at 30 degrees.  The image on the left side has an angle between adjacent element normals close to 180 degrees and therefore does not meet the criteria of the 30 degree threshold.  The image on the right has the angle between normals less than 30 degrees, and the threshold criteria for feature angle is satisfied.  However, this could be a modeling discrepancy that should be accounted for, perhaps allowing the averaging of values for elements on the left image, but not allowing averaging of elements on the right image.  This can be accomplished by activating the Ignore flipped normals option.

If strict adherence to the angle between adjacent element normals is to be enforced, then uncheck this option.

Note - The Legend will automatically update and reflect that feature angle averaging is activated.

The following options allow you to control the current iso value displayed on the screen.

Current value

The current iso value that you want displayed.

iso_current_value

The slider bar allows you to increase or decrease the current iso value.

Increment by

The incremental value used when moving the slider bar.

Once an iso surface is created, you can use the following options to select how model elements are displayed:

Show

Equal

Updates the graphics display so that all elements with result values equal to the current iso surface level are displayed (unmasked) based on their display attributes defined on the Entity Attributes panel.


Above

Updates the graphics display so that all elements with result values above the current iso surface level are displayed (unmasked) based on their display attributes defined on the Entity Attributes panel.


Below

Updates the graphics display so that all elements with result values below the current iso surface level are displayed (unmasked) based on their display attributes defined on the Entity Attributes panel.

Color

Select a vector color from the palette.

Clipped
geometry

Features

Displays the feature lines of the components (parts) which have iso values applied to them.


Transparent

Displays the components (parts) which have iso values applied to them as a transparent surface.

Clear Iso

Removes iso surfaces from the model.

How do I...

hmtoggle_plus1Create iso surfaces for nodal results:
1.From the Iso panel, Result type drop-down menu, select the data type that should be used to calculate the iso values.
2.Select a data component from the second drop-down menu below Result type.
3.For Selection, pick one or more components from the model.
4.For Resolved in, select the coordinate system that will be used to calculate the results.
-If User System is selected, use the System input collector to select a system by ID.
5.Click Apply. The model is displayed in iso value mode.
hmtoggle_plus1Create iso surfaces for elemental results:
1.From the Iso panel, Result type drop-down menu, select the data type that should be used to calculate the iso values.
2.Select the data component from the second drop-down menu below Result type.
3.If the element has layers defined, select the relevant option for Entity with layers.  
4.If corner data is available, activate Use corner data to display color bands by interpolating available corner results within each element.
5.For Selection, pick one or more components from the model.
6.For Resolved in, select the coordinate system that will be used to calculate the results.
-If User System is selected, use the System input collector to select a system by ID.
7.Select an averaging method. Simple is the default setting.
8.Activate Use variation (%) and enter a percentage for the variation range.
9.Click Apply.
hmtoggle_plus1Create iso surfaces using contour results:
1.From the Iso panel, click Use Contour Settings. The settings from the Contour panel are copied to this panel.
2.Click Apply. The model is displayed in iso value mode.  Use the slider bar to display the value of interest.
hmtoggle_plus1Change the display of model elements:
1.From the Iso panel, enter a value in the Current value text box or use the slider bar to display a specific value.
2.Change the value in the Increment by text box to adjust the slider bar movement.
3.Select an option for Show values to display elements based on result values.
4.Activate the Color check box, then click the color button to select a vector color from the palette.
hmtoggle_plus1View iso value with transparent boundary geometry as "x-ray" viewing:
1.From the Iso panel, click Use Contour Settings. The settings from the Contour panel are copied to this panel.
2.Click Apply. The model is displayed in iso value mode.  Use the iso value slider bar to display the value of interest.
3.Click in the graphics area and press "T" on the keyboard to turn on the Transparent Boundary Geometry option.
4.Press "L" on the keyboard to display boundary geometry feature lines.
5.Use the slider bar to optimize the visualization of critical areas.

Note        The Transparent and Features options can also be toggled on or off using the Boundary Geometry option on the Display Control menu on the toolbar.

 

See also

Layer Filter

List of Tcl/Tk poIIsoValueCtrl Class commands