FEA, which stands for finite element analysis was originally developed for solving solid mechanics problems but is now adapted as a method for solving multi-physics problems.
Some examples of FEA applications are listed below:
- Vibration of the USX tower in downtown Pittsburgh
- Thermal stress on a gear shaft in your car
- Cantilever beam deflection off an oil platform
FEA’s primary goal is to answer the question: If a force is applied on a solid, then what are the values of displacement, stress, and strain at EACH MATERIAL POINT? To do such a task would take hours, even days of computations involving calculus and other complex procedures. Luckily, there are numerous software packages on the market that boast unique features and make the analysis easier and less time consuming than if it was done with pen and paper.
The general procedure for any FEA software today is as follows:
- Describe the problem: simplifying or idealizing a real engineering problem that can be solved by FEA.
- FEA Model (pre-processing): within the software discretize/mesh the solid, define the material properties, and apply the boundary conditions.
- FEA Theory (analysis): Applying the FEA theory where one chooses approximate functions, formulates linear equations, and solves such equations.
- This is the core of the analysis, but it is also heavily math based and sometimes can be arduous and cumbersome.
- Results (post-processing): obtain, document, visualize, and explain the results to a manager or potential client.
My hope is to shed some light on the question “which FEA package is best” and which one preforms the above process most effectively?
Speaking from both experience and ethics, which software is “best” is a rather straightforward and easy question to answer. It is the software that predicts the most accurate results with regard to reality. What often happens in debates such as these is engineers get caught up in how easy the software is to use or how much storage it uses up that they lose sight of the end goal: accuracy and safety.
With any FEA problem, one is designing a part or structure to be used by others such as a bridge support, combustion engine, or aircraft wing. Failure of any of the previously listed examples due to a botched FEA analysis because of bad software results in harm to the end user. A sobering thought, right? So above all, make sure your software is precise.
Furthermore, the accuracy and precision often depends on your application. Not every software can preform every type of problem. Therefore, before selecting which package to use or learn, the engineer needs to define what kind of problem they will be doing most often?
- Linear static
- Natural frequencies
- Transient response
- Pressure vessels
- CAD integration, etc.
Some packages such as Elmer are free, boast high accuracy, and does natural frequency work rather well, but does not do non-linear equations or have a graphical geometry modeler. On the other hand, EngiLab Beam.2D does even touch natural frequency work but is excellent when it comes to linear static problems. Therefore, before looking at which software to learn or even buy, put in your homework and research the multitude of software available. If you do not know where to start, FEA Compare is a great website that offers a side by side comparison chart of 72 mechanical FEA programs.
In my opinion though, I find ANSYS to be the premier FEA software. It is by far the most versatile and has the capability of preforming any FEA based problem. Furthermore, it is the main software used in industry and manufacturing whereas an equally competent and versatile software called ABAQUS, is mainly used by academia and research.
ANSYS is not the easiest software to use, but it has a more flexible and responsive information-based development process enabling modifications at later stages in the analysis, a rare feature not found in competitors software. You can also integrate CAD models into the software relatively easily and preform CFD operations on the model (a feature that is a favorite of mine). Overall, ANSYS can be adapted to any engineering problem making it indispensable to a college undergrad and if you have the time, take the time to learn it thoroughly.