Quality Index Panel

Use the Quality Index panel to calculate a single value to represent the quality of the displayed shell (2-D) model. Criteria settings are stored and retrieved using a criteria file. You can save the results from the Quality Index (QI) panel to a summary file.

Note:

See How Element Quality is Calculated in the Meshing chapter of the HyperMesh User's Guide for details on how quality is calculated depending on solver profile.

When you open the Quality Index panel, HyperMesh changes the color of the elements according to how well they adhere to the pre-set quality requirements, rather than according to their component or any other visualization mode chosen.

QI_visualization

Panel Usage

On the right-hand side of the panel, you can review the compound Quality Index, as well as the number of elements and the percentage of elements that failed a quality check. To highlight elements falling at or below a certain quality level, move the display thresholds slider. Lastly, you can access the cleanup tools and save a list of failed elements.

The left-hand portion of the Quality Index panel consists of four pages; the current page number displays in the upper-left corner of the panel. To either side of the page number, a small arrow button allows you to page forward or backward to view the other pages. In addition, one column on pages 1 and 2 includes a toggle at the column heading; use this toggle to switch the column between displaying the worst quality value found for each quality check, or the total Q.I. value generated by each check.

QI_panel

Subpanels and Inputs

There are no subpanels on the Quality Index panel, but there are three pages of criteria accessed via the page arrow buttons.

Panel Inputs

Input

Action

< page >

This combination of a left-arrow, text label, and right-arrow allow you to advance or recede through the pages of criteria.

display thresholds

This combination of a slider and buttons (one button for each quality level) display on every page.

allows you to visually identify all of the elements at or below a certain quality level. For example, setting the slider to "warn" will highlight all elements in the model whose assessed quality level is "warn" or worse — in other words, elements at the "warn", "fail", and "worse" quality levels.

Note:

The buttons under the slider also act as to slider position labels. Clicking one of these buttons automatically repositions the slider to rest right above that button.

For information on the different checks used in the Quality Index panel refer to How Element Quality is Calculated.

Panel Inputs

Criteria	Description
color legend	Use these buttons to change the colors that elements highlight when they fall within each quality category.
display summary legend	When this checkbox is active, a text-based summary of the number of elements failing each check displays in the graphics area on the criteria pages (pg1 and pg2).
allow to move fixed and shared nodes	When enabled, nodes shared between components, or nodes belonging to both solid and shell elements, are allowed to be moved when you are using the modify hole & washers cleanup tool, and the link washers checkbox is enabled.
set max failed elements to save	Select this check box if you would like to specify how many elements should be saved to the mark when you click save failed. When this option is on, an entry field to enter the number of elements is available. If you set it to 10, the 10 elements that have the worst QI value will be saved to the mark when you click save failed. This option allows you to fix a few failed elements at a time.
summary file	You can save the quality results of the selected model to this file (summary file). It exports all the information seen in the results pages of this panel. In addition, it records the IDs of the three elements that have the worst quality result for each criterion.
save	Click this to save the summary file.
edit criteria	Click this button to open the criteria file editor, from which you can load, save, and modify files that contain the criteria used by the Quality Index panel.

The following action buttons appear:

Button	Action
cleanup tools	Opens the temporary QI cleanup tools secondary panel, where you can manually alter the placement of nodes to improve local quality.
save failed	Saves all the elements that failed at least one criterion. The elements are saved in a mark and can be obtained in other panels using the retrieve extended entity selection option
abort	Exit the panel, discarding changes.
return	Exit the panel, keeping changes.

How do I…

1.	Select the Quality Index panel.

2.	Ensure that place node is highlighted.

3.	Pick the node you want to move and, while holding the mouse button down, drag it to the desired location.

4.	Release the mouse button.

Comments

As you move the node, the colors of the attached elements will change, as its Q.I. changes.

If the elements you brought into the element cleanup module are attached to a surface, then the node is constrained to move only on that surface. Otherwise, a surface from the mesh of elements is inferred and constrains the node to move only on the mesh.

As you hold down the mouse button on a node and manually move it, the comp QI displayed in the results page reflects the local QI of all the elements that are attached to the node you are moving. The # of quads, # of trias, % trias, and # failed also reflect the local elements that are affected. Once you release the mouse button after positioning your node, the panel is updated to reflect the QI of all the elements (not just the local element).

1.	Select the Quality Index panel.

2.	Click swap edge to highlight it.

3.	Pick the edge you want to switch.

Comments

For a pair of trias, there are two possible positions for their shared edge. For a pair of quads, there are three possible positions. For a quad and a tria, there are six possible positions. Each time you pick the edge, it switches to the next valid configuration.

1.	Select the Quality Index panel.

2.	Click node optimize to highlight it.

3.	Pick the node whose position you want to optimize.

QI_node_optimize

HyperMesh automatically moves the selected node to an optimized position.

Comments:

The node placement is optimized to obtain the best QI for all the elements surrounding that node. The element optimization also works similarly. It optimizes the position of all the nodes of the element, attempting to make the element more geometrically balanced. Thus quads will become squarer, and trias will become closer to being equilateral triangles. This function also honors the feature lines (using feature angle from the options panel) and free edges. Thus the nodes are moved only along those lines. For example, on a 2-D surface with a crease in it, a node located on the crease will not move off of the crease. The resulting element may still be imperfect, but this is preferable to an element that extends over bends in the surface or beyond the surface’s free edges.

1.	Select the Quality Index panel.

2.	Select pg4.

3.	Enter a summary file name for summary file:.

4.	Click save.

1.	Select the Quality Index panel.

2.	Click save failed.

Comments

This function replaces elements that were previously on the user mark.

Once the failed elements have been saved, the user mark can be loaded into other panels.

Quality Index Panel

Quality Index Panel

Quality Index Panel

Panel Usage

Subpanels and Inputs

Panel Inputs

< page >

display thresholds

Panel Inputs

color legend

display summary legend

allow to move fixed and shared nodes

set max failed elements to save

summary file

save

edit criteria

cleanup tools

save failed

abort

return

How do I…

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