Simulation Troubleshooting 101

I was teaching a SolidWorks Simulation class a few weeks ago and a student asked me a question which gave me a great idea for a blog topic. He asked if there was a certain process we go through to troubleshoot a customer's file if their Simulation throws out an error somewhere during meshing or running. There are a few places you could see an error message so I'll start with the two most common and ask anyone reading this to throw out any ideas or problems you have run into when running a Simulation study.

1.  An error occurs when meshing

This is a common problem when trying to mesh small geometry with a coarse mesh. There are other factors that could potentially cause mesh failure, but mesh size is the most common. The approach I normally take when troubleshooting mesh failures is to use Tools > Check as suggested by the Mesh Failure Diagnostics. This tool checks for bad geometry in the model which could cause meshing problems. Bad geometry isn't often the cause of mesh failures, but it's a very easy thing to check first to rule it out.

Another thing that's usually quick and easy to test is switching the mesher type from Standard to Curvature Based, or the other way around. Sometimes one mesher will fail while the other is successful. This is usually a simple thing to try so it's high on the troubleshooting list.

The next thing I do is take advantage of the Mesh Failure Diagnostics and figure out which face failed to mesh. Once you know which face failed, it's much easier to come up with a solution. Typically a Mesh Control on a failed face will solve the issue. Trying an incompatible mesh is another option provided by the Mesh Failure Diagnostics and is an easy one to try as well.

2.  An error occurs when solving

Solver errors are more common than meshing errors and harder to troubleshoot, but often the error can indicate where to look for the problem.  Seeing an error like this would lead me to look at the fixtures first. Sometimes an error pops up that just says "Solver Failed" which doesn't give you an indication where to look. The first step will be the easiest, make sure all components have a material assigned. Once that's verified, the fixtures/ connections are the next place to look.

To easily troubleshoot fixture issues, simply add a new Fixed Geometry fixture to one face of every component in the model. The results will obviously not be accurate, but if the solution completes you know there is something unrestrained in the model you need to dig further into. If you see the same error, it's time to move on from the fixtures.

When trying to troubleshoot problems on your own Simulation study it's best to take a step back and not care about the model for a minute. What I mean by that is don't worry about which components should have which material, only that they have a material applied. Don't worry that fixing a face on every component will make the results inaccurate, at least the study solves and now you know the fixtures or connections are the problem. Once we get a better understanding of where the problem is happening, finding a solution should be much easier.

The steps I covered are pretty basics steps that I find easiest to test first. Please share your thoughts if you have other "Go To" Simulation Study troubleshooting techniques that have helped you out in the past.