Preparing Your Geometry for Solidworks Simulation

Before we go ahead and analyse our structure in Solidworks Simulation we need to consider if the geometry is suitable for finite element analysis.

Some of the things that need to be investigated before starting the analysis include

• What parts need to be analysed
• Can you use simulation features to replace parts
• Is the geometry suitable for the mesh
• Can the geometry be simplified
• Are there any problems with the geometry

A good approach to simulation is start simple and add complexity.  This applies to the geometry as well as the simulation setup.  Consider starting with a part or just a few parts and get a small simple analysis running and then add complexity. Starting with a large assembly and creating a study without even considering if the geometry is suitable to use in finite element analysis will cause problems.  For instance, interference is not supported (except with shrink fit analysis) so before starting an analysis on an assembly or multibody part you will need to analyse for interference and remove it.  This can be done using Tools-> evaluate-> interference detection.

Consider if you remove parts altogether.

Can you simplify the assembly by removing bodies that don’t need to be analysed and replace them with forces or restraints?  Or can you replace then with simulation features such as remote masses, rigid parts, virtual walls, bolt, pins, bearings, links, or rigid connection etc.

Do you need to change the geometry?

Consider what type of mesh you will use, if you are going to use a shell mesh do you need to create mid-surfaces and remove the solid geometry?
Can you use symmetry?  This one is missed all too often.  If the geometry, loads and response are symmetric you can cut your model in half reducing setup and run times and adding stability.
Do you need to change the geometry to be better suited to mesh and bond?  For example, can you remove gaps between solids and shells and merge bodies if they are going to be bonded and made of the same material? It might seem trivial with a few bodies but when you have many bodies it makes setting up and modifying the simulation faster.  Should you split faces to ensure compatible mesh?
Remember you can save an assembly as a part which can make working with the bodies easier.

Can you need to Simplify and defeature?

The more complex the geometry, the smaller the elements that are required to conform to the geometry resulting in more complex mesh and longer running times. Can you remove unnecessary features that do not impact the structural integrity i.e. the strength or stiffness.  For example, cosmetic features like logos, external fillets, small holes and small entities. There is a utility that can assist with this process.  On the analysis preparation tab, you will find a simplify command.  This allows you to create a new configuration without unrequired features.

For further information see http://help.solidworks.com/2019/english/SolidWorks/sldworks/t_simplifying_parts.htm

Lastly are there geometry problems that would prevent the geometry being meshed successfully?

Small or invalid geometry can cause the mesh to fail.  To identify these, we can use the following 2 tools.
1. Check.  Found under Tool-> evaluate -> or on the evaluate tab.
2. Geometry analysis. Found under Tools-> Geometry analysis or on the evaluate tab.

These tools analyse the geometry and identifies potentially problematic geometry such as invalid faces and edges as well as short edges, small faces, silver surfaces and discontinuous edges and faces.

For further information on how to use these see the Solidworks Help.

Bianca Roberts
Applications Engineer
Central Innovation, Melbourne

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