Mesh Tolerance Settings

File: PVE-4048
Last Updated: FEb 17 2010
Laurence Brundrett

What impact does the mesh tolerance option have on the mesh produced by SolidWorks Simulation?

Caution: every time the mesh size is changed, the tolerance is adjusted to 5% of the mesh size. This is a very nasty feature! Keep your eye on the tolerance and set it back the to value you require after each mesh size change.

External Features

As the mesh tolerance increases, exterior model details disappear from the mesh. This block is 5 x 5 x 1 inch high. Each feature is 1 x 1 inch. Feature height changes as shown.

SolidWorks Simulation can mesh the object with very coarse mesh sizes, as long as the tolerance is fine enough:

Run #1, the mesh size is at 1 inch and the tolerance at the cosmos default 0.05 inch (5% of mesh size). When the tolerance is increased to or above the size of a feature, it disappears from the mesh.		Run #2, the mesh size is still at 1 inch, but the tolerance is increased to 0.125 inch (the height of the first feature). The first feature disappears.
Run #4, the tolerance is at 0.26 inch, the second feature disappears (the center of it still exists, but the edges are gone).		Run #8, the mesh size is 1.125 inch and the tolerance 1 inch, all features and much of the base disappears. The mesh does not have to be smaller than the feature size modeled.
Run #9, The mesh size is 2.5 inch, but the small features are still modeled because the tolerance is set to 0.05 inch.

Internal Features

Slightly different results are achieved with internal cut features.

Here the extruded bosses are replaced with cut slots: 1, 0.5, 0.25 and 0.125" wide all the way through the same 5 x 5 x 1" block. When the tolerance is too coarse, the mesh fails:

Watch for this reason for mesh failure. If the cut features are not desired in the mesh, they have to be removed from the model.