Is This a Good FEA Mesh? Here’s How to Answer Yes, No, and All-You-Need-to-Know About Meshing Infographic
Meshing a model is an integral step in performing any simulation. There’s no getting around it – it has to be done. Thanks to many improvements over the years, meshing has transformed from a very tedious, manual process into a quick and easy automated one. Even though SOLIDWORKS Simulation has countless tools and techniques to make meshing as easy as possible, a level of confidence in the resulting mesh can be lacking in even the most advanced users. Is it a good mesh? It’s a simple question with a yes or no answer, and yet we all sometimes have difficulty answering it with confidence. Here’s how to know if you have a good mesh or not.
The answer lies in the “details.” Right click on mesh in the Simulation Tree and click details. From here you will see a lot of information about your mesh that can help you make informed decisions about your simulation. Specifically, you will be able to qualify whether or not the mesh is in fact good. For this, look at these particular quantities all pertaining to the aspect ratio:
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Maximum Aspect Ratio
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Percentage of elements with Aspect Ratio < 3
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Percentage of elements with Aspect Ratio > 10
The Aspect Ratio quantifies the quality of the elements, where 1 is a perfectly shaped tetrahedral element and the element shape is worse with a higher Aspect Ratio. You can see this in the image to the left. The aspect ratio is defined as the ratio of the shortest length of the element to the longest length of the element.
Since a mesh is nothing more than an approximation of your geometry broken down in to tiny pieces, it is reasonable to have some not exactly perfect elements in your model. In other words, a good mesh won’t be made up entirely of perfectly shaped elements. A good mesh will, however, have nearly all of its elements with a small aspect ratio or a value less than 3. Although this won’t always be possible especially with larger more complicated models. So keep in mind when doing any subsequent levels of mesh refinement it might not be worth the time investment to improve just a handful of elements out of the thousands in the entire model.
If you want to be able to quickly determine if you have a good mesh, here’s what you need to know: