A common concern I hear when presenting SOLIDWORKS Simulation is whether or not the results are accurate. This is a difficult – if not impossible – thing to prove without empirical data to back up the results. To reassure those concerned, I usually rely upon the ‘Validation Examples’ included in SOLIDWORKS and verified by NAFEMS, which may or may not leave the audience more confused in the end. In an attempt to fully explain NAFEMS and why it should be reassuring, I present you my latest blog installment.
Who is NAFEMS?
Let’s start with a short history on NAFEMS and an explanation of what they do. NAFEMS was founded in 1983 as a response to exactly what I was mentioning in the introduction of this article: concern over the reliability and accuracy of FEA results. Glad to hear it’s not just me!
As increased computing power became more widely available in the 70’s and 80’s, FEA adoption and use became more prevalent. The relatively quick adoptions lead to inexperienced users as well as questionable code and accuracy. It was at this time the UK Government’s Department of Trade and Industry (DTI) funded a project within the National Engineering Laboratory (NEL) to investigate these issues. This was the beginning of NAFEMS, or the National Agency for Finite Element Methods and Standards.
Simulation Benchmarks
The initial aim of NAFEMS, and the way in which it relates to SOLIDWORKS, was to develop standard ‘benchmarks’ to which codes could be compared. In the most recent release of SolidWorks there are over 50 NAFEMS benchmarks compared over 6 different categories.
NAFEMS Benchmarks
Sample Results
For each benchmark you’re presented with the theoretical result and those found in SOLIDWORKS Simulation. A screenshot from one such benchmark (Vibrations of a Simply-Supported Thin Annular Plate) can be seen below:
Benchmark Results Example
What about numerical discrepancy?
As expected, there is some amount of discrepancy, but we all understand FEA is a numerical method intended to give approximate solutions, right? Numerical discrepancy could be the subject of another blog entry, but in most cases being within ±5 percent will provide engineers confidence to make positive design decisions.
Today NAFEMS goes beyond benchmarks; they are involved in many aspects including advocating for simulation use, education, and training of best practice techniques. Take a look at the NAFEMS website if you’d like to learn more. In addition to NAFEMS, other organizations are entering this realm including ISO and AFNOR, the French national organization for standards.
Now, if I could just figure out how to pronounce ‘NAFEMS’ properly…
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