Almost all the solid element meshes I come across in the last decade or so have used second order 10 noded tetrahedral elements, and for most applications they are perfectly fine. There are however some applications in some FEA solvers that require a hex8 element – for example some elastomer models, magneto and electro static solvers and some acoustic solutions. How do you mesh an irregular part in hex elements?
Traditionally you use a combination of extruding and revolving a 2D planar mesh on various surfaces or cross-sections. Re-meshing such a scheme means effectively starting from scratch.
Some meshers support 2.5D hex meshing – a scenario where you have opposite ends of a part being topologically identical but the sides being plain, like this:
Breaking a more complex solid into smaller pieces that can be 2.5D meshed and then applying those meshes in a way that maintains homogeneity across solid boundaries can be a complex and slow manual process.
The Grizzly release of MSC Software’s Apex software introduces a methodology to make this process very simple. Instead of splitting the solid into multiple new solids it allows you to partition the solid into cells. There’s an interactive traffic-light display that colour codes the solid as you go, turning the cells to green as they become meshable. The tool follows the Apex ethos of being intuitive and easy to learn. We find little or no training necessary for new users to get to grips with the Apex interface.
This short video shows an example of using the methodology to create a solid mesh on a part. For comparison this video takes 3m25s to go from importing the model to having a solid mesh. In Patran performing the same sort of operations using the mesh morph tool took me nearly an hour with many, many more mouse clicks and would require most of that time again to change the mesh refinement, whereas Apex would take just six clicks and less than a minute.
MSC Apex is available under the MSC One token licensing system. It has many powerful tools for de-featuring geometry, extracting mid-planes and meshing in addition to the capability shown here. A single license of this could cost you just under £2400 per year. How many hours of geometry clean up and meshing would you need to save in order to justify that cost?
Please get in touch if you’d like to have a trial of this powerful new tool.