Hexa Meshing
Altair EmployeeHello Everybody,
I am trying to bring a good quality hexa mesh. The mesh I am getting is good in almost all the quality criteria except 'aspect ratio'. I am getting the aspect ratio values in range 3 to 5. I have read that the acceptable aspect ratio is below 5, so my mesh should work. But what I am expecting is to get a good quality mesh in the area since it may be the region of high stress. My question is how good my mesh is if it is to rate between 1 to 10? (I am getting a very good mesh for rest of the quality criteria) And to what extent my results may get affected if I fail to bring a proper mesh in the region?
The attached illustrative image may be referred. The 3D mesh will be connected to 2D mesh and the the analysis is explicit (Radioss).
Please advise.
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Answers
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Hi,
A good mesh depends on various factors like element type used, element size, element quality....etc. So it is difficult to comment how good is this mesh, but based on the quality parameters and mesh it seems fine.
The critical regions are where we expect high stresses and those areas has to be captured well. In those regions choose a mesh size that is small enough to accurately follow the shape of the parts, particularly around small features in critical regions. Mesh density is a significant metric used to control accuracy of results. A high-density mesh will produce results with high accuracy. However, if a mesh is too dense, the overall number of elements and resulting degrees of freedom will be high, requiring a large amount of computer memory and long run times.
The most basic and accurate way to evaluate mesh quality is to refine the mesh until a critical result such as the maximum stress in a specific location doesn’t change significantly as the mesh is refined.
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Altair Forum User said:
Hi,
A good mesh depends on various factors like element type used, element size, element quality....etc. So it is difficult to comment how good is this mesh, but based on the quality parameters and mesh it seems fine.
The critical regions are where we expect high stresses and those areas has to be captured well. In those regions choose a mesh size that is small enough to accurately follow the shape of the parts, particularly around small features in critical regions. Mesh density is a significant metric used to control accuracy of results. A high-density mesh will produce results with high accuracy. However, if a mesh is too dense, the overall number of elements and resulting degrees of freedom will be high, requiring a large amount of computer memory and long run times.
The most basic and accurate way to evaluate mesh quality is to refine the mesh until a critical result such as the maximum stress in a specific location doesn’t change significantly as the mesh is refined.
Thank you sir!
The minimum length in my case here is 1.5 mm and with that I am getting the aforementioned aspect ratios. Since I am solving the problem in Radioss, with a transient load, I also need to take care of the time step. Apart from the element type used is my mesh still okay?
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Hi,
The mesh seems okay. Please run the analysis and we will review the results.
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Your mesh looks good. But it's possible to do that better.
In fact, in FEA world, we have to know where we have to ... stop to get something acceptable :-)
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