Abstract
Written for non-engineering audiences – a basic introduction to Finite Element Analysis (FEA) covering the digital modeling process, meshing, load and constraint application, and interpretation of stress and displacement results.
What is Finite Element Analysis (FEA) ?
Finite Element Analysis (FEA) is a computer simulation technique used to evaluate whether a component or system will hold up under real-world conditions — before it’s built, tested, or put into service.
In practice, an engineer creates a digital model of the structure and subjects it to the forces it will actually experience: mechanical loads, temperature changes, vibration, seismic events, or internal pressure. The software divides the model into thousands of small segments — called finite elements — and solves the governing equations across each one, showing where stress concentrates, where deformation occurs, and where failure is most likely to begin.
FEA can handle both simple and complex geometries, and it accounts for materials that respond predictably under low loads as well as those that behave differently once stress exceeds a threshold. When done right, FEA is an efficient tool for evaluating structural integrity, particularly for complex geometries and loading conditions where hand calculations fall short. It doesn’t replace physical testing or classical engineering checks — it complements them, often at a fraction of the time and cost. O’Donnell Consulting has applied FEA for over 30 years across industries ranging from nuclear power to petrochemical, using it to support equipment design, code compliance, failure analysis, and expert witness work.
For more details, see History of FEA.
Why Do I Need FEA?
Finite element analysis, when properly applied by experienced engineers, provides an accurate response of a structure from imposed loads and constraints.
Typical reasons why FEA is performed:
- For a manufacturer who is required to meet specific structural codes and standards.
- As a plant owner/operator – it is a useful tool for helping to identify the cause of a failure and perform subsequent redesigns.
- If you’re involved in litigation, FEA (where applicable) is used to develop models to clarify the root cause –
enabling judges and juries to easily understand the technical issues.
What’s Involved in Performing a Finite Element Analysis?
Practical finite element analysis requires sophisticated software. There are various commercial and non-commercial software programs available, with varying capabilities. The entity to be analyzed needs to be represented mathematically, such as a three-dimensional Computer Aided Design/Drafting (CAD) model.
The CAD geometry model is subsequently discretized into small finite segments referred to as finite elements. As seen in the above images – the dam gate is meshed into numerous three-dimensional elements. Correct meshing is one of the critical parts to the analysis. Complex equations governing the behavior of each element and compatibility between them is mathematically enforced. All of this is performed by the FEA software. See below for a simple demonstration of how FEA works.
What Do I Get out of a Finite Element Analysis?
Analysis results are most commonly presented as color contour plots and or displaced shapes of the result(s) of interest (e.g. stress level or displacement magnitude, etc.). With this approach, critical regions can quickly be identified. The quality of FEA results is highly dependent on the quality of the input data. FEA models/analyses results should always be assessed against results obtained with classical engineering equations or other known solutions.
The Bottom Line….
More and more, product suppliers and end users are recognizing the benefits of FEA and are requesting this type of design assessment from manufacturers and fabricators. With the ever- increasing speed of personal computers and accessibility of cloud-based computing to both individuals and large corporations, FEA has become a standard tool for anyone involved in design / component / system/ structure evaluation. Software companies are responding by integrating simulation tools directly within the CAD environment along with the ability for “instant” simulation.
As with any other tool, it is important to understand the limitations and proper use. Anyone can perform a finite element analysis. However, getting it done right requires attention to detail and a critical eye.
