element quality plots in ansys wb 16

Home (/) Support ANSYS Tips & Tricks FEA

Figure 1: Colored Mesh Quality Plot in ANSYS Mechanical (Workbench) 16.0

ANSYS Mechanical (Workbench) 16.0 makes it easy to review element quality during the development of meshing controls, as well as inpostprocessing results. Well-shaped elements yield superior results, and help reduce element shape errors during large displacementanalysis, such as when using hyperelastic materials with substantial strain.

This article briefly reviews features in the Workbench Mechanical Outline for displaying element quality (1) in color in the Mesh branch, (2)using bar charts of element quality, and (3) plotting element quality in postprocessing after element shapes have been distorted by strain ina model..

Three Element Quality TechniquesWorkbench Mechanical 16.0 has a new feature for reviewing element quality at the Mesh branch, in order to review the consequences ofmeshing controls prior to solving a model. First, though, here is a view of mesh metrics as they have been measured in WorkbenchMechanical in the last few versions of the software:

(http://www.simutechgroup.com)

ELEMENT QUALITY PLOTS IN ANSYS MECHANICAL (WORKBENCH)16.0 (/FEA/FEA-TIPS-TRICKS-ELEMENT-PLOTS-ANSYS-16.HTML)

HOME (/) SOFTWARE CONSULTING TESTING INDUSTRY SUPPORT TRAINING

BLOG (HTTP://BLOG.SIMUTECHGROUP.COM/) CONTACT US (/OFFICES/) ABOUT US

Element Quality Plots in ANSYS Mechanical (Workbench) 16.0 | FEA ... http://www.simutechgroup.com/FEA/fea-tips-tricks-element-plots-ansys-...

1 of 6 3/18/2015 6:38 PM

Figure 2: Mesh Metrics in a Coarse Tet Mesh

To get the above view of mesh Metrics, click the Mesh branch in the Outline, go to Details of Mesh, open the Statistics section of theDetails, and use the drop-down list for Mesh Metric to select the metric of interestin the above Figure 2, Element Quality has beenchosen. Many choices are available:

Figure 3: Mesh Metric Selection

As seen above in Figure 3, the full listing of Mesh Metrics in the Mesh branch in 16.0 is:

NoneElement QualityAspect RatioJacobian RatioWarping FactorParallel DeviationMaximum Corner AngleSkewnessOrthogonal Quality

After choosing a quality metric, a bar chart is generated showing how many elements fall into ten Element Metrics zones. If one of the tenbars in the chart is clicked by the user with the cursor, then the elements that fall into the zone of that Element Metric are displayed in theGraphics Window. In Figure 4 below, the bar with Element Quality around 0.5 has been clicked, and elements with that quality are shown inthe Graphics Window, with the geometry shown translucent in order to give context to the element locations:


2 of 6 3/18/2015 6:38 PM

Figure 4: Elements Falling into a Mesh Matrics Zone

The second means of viewing element quality is to create color plots. What is new in 16.0 is the ability to produce color charts of a variety ofelement quality metrics. As seen in Figure 5 below, a mesh quality assessment can be shown in a color plot at the Mesh branch.

Figure 5: Colored Element Quality Plot at the Mesh Branch in v16.0

Note first that in order to get the color plots of element quality, in the Statistics section of Details of Mesh, the Mesh Metric must be set toNone, as seen in Figure 5. In the Display Style section of Details of Mesh a number of choices are available:

Figure 6: Display Style Selection for Element Quality Type


3 of 6 3/18/2015 6:38 PM

Element coloring is controlled by the Display Style drop-down list, as seen in Figure 6 above. Body Color does not show an elementquality assessment. The quality plot choices are:

Element QualityAspect RatioJacobian RatioWarping FactorParallel DeviationMaximum Corner AngleSkewnessOrthogonal Quality

Note that some choices for color plots of element quality are not applicable to tetrahedral elements, such as Parallel Deviation, whichproduces a blank or null result.

The third type of element quality assessment that is available is in postprocessing. The elements in their deformed shape are assessed, ata solution time that can be set by the user. The plots are from the User Defined Results list.

Figure 7: Postprocessing Element Shape Quality with User Defined Results

In Figure 7 above, note that several element shape quality assessments can be chosen from the listing of User Defined Results. Theyinclude:

Element QualityAspect RatioJacobian RatioWarping FactorParallel DeviationMaximum Corner AngleSkewness

Note that some choices, such as Parallel Deviation, are not applicable to tetrahedral elements, and will produce a null result. Aspostprocessing results, the element shapes are assessed in the element deformed condition, with element deformation a consequence ofstrain in the model. The time of the plot produced will default to Last, but can be set by a user to any preferred time value. Figure 8 belowillustrates.


4 of 6 3/18/2015 6:38 PM

Figure 8: Mesh Element Quality for Deformed Elements at Time=2.0

In Figure 8, the Element Quality shape assessment has been performed on element shapes as deformed by the solution. In the TabularData for this solution result, note the difference in the Minimum and Maximum values at Time values of 1.0 and 2.0. This difference is aresult of changing loads on the model between times of 1.0 and 2.0.

ConclusionsWorkbench Mechanical 16.0 offers three ways to view element shape quality assessments.

While preprocessing, color plots of element quality can be performed by choosing Mesh branch details Display Style drop-down list values,while keeping the Mesh Metric choice set to None.

At the Mesh branch, a user can go to Details and use the Statistics >Mesh Metric choice to produce bar charts of the range of a number ofelement shape assessments.

When evaluating Solution results, User Defined Results can be created for several element shape assessments, which are applied to thedeformed elements, yielding colored plots.

In the colored plots, values in the Legend can be user-adjusted, and other review tools can be employed, such as Probe, Min and Max, andthe usual contour controls.


5 of 6 3/18/2015 6:38 PM

element quality plots in ansys wb 16

Documents