What is Finite Element Analysis (FEA)?
Finite element analysis (FEA) is the process of predicting the behavior of an object based on calculations performed with the finite element method (FEM). While FEM is a mathematical technique, FEA is the interpretation of the results provided by FEM. FEA helps engineers make more informed design decisions by providing insights into complex systems and structures.
FEM uses mathematics to break down complex systems into smaller, simpler parts or “elements”. Then, using the power of computers, it applies differential equations to each element individually to divide and then conquer engineering problems.
FEA is the application of FEM equations and is the foundation of many simulation software. It is used to verify and test designs safely, quickly and economically by creating virtual models of real-world entities.
Finite element modeling makes it possible to simulate the physical world without the expense, time or risk of building physical prototypes. These models are used to solve various conditions and scenarios in various industries, especially those with complex or high-risk environments, such as aerospace and biomechanics.
Finite Element Analysis Examples
The chair you are sitting on. Your wireless phone charger. The blood flowing in your veins. All around us are objects and systems that can be modeled using FEA. With its ability to predict problems with highly irregular dimensions, FEA can be applied to almost anything. Any physical behavior described using differential equations, such as most engineering problems and even certain esoteric problems like quantum mechanics, can be solved using FEA.
FEA is widely used in industries where physical testing is impossible or impractical. Examples of applications using FEA models are:
Civil Engineering: FEA is used to assess the safety and integrity of structures such as bridges, buildings and dams. FEA can help engineers optimize their designs to meet safety standards and predict maintenance needs.
Aerospace Engineering: FEA is used to simulate the performance of aircraft components and systems against many different flight conditions. Landing gear integrity, aerodynamics, thermal stress, fatigue life prediction, vibrations, fuel usage and more can be modeled using FEA.
Automotive Engineering: FEA is used to evaluate systems in a vehicle, including head-up displays, battery life, exterior lighting and structural crashworthiness. In safety testing, FEA can help engineers evaluate the performance of various safety systems under various impact conditions.
How Does Finite Element Analysis Work?
Finite Element Analysis works by decomposing the domain of interest and then putting together the equations of physics to solve the engineering problem at hand. By putting these elements together to represent the physical system, engineers can predict the behavior of the entire structure. With FEA, answering the question, “Will my car be safe after being driven over 100,000 miles?” begins by breaking the car into systems, systems into components, and components into elements using a grid of elements known as meshing.
Finite Element Analysis Process
Pre-processing: Define the physics and real world conditions to be used in the model.
Process: Divide the object into finite elements by meshing and apply the relevant physics representations and/or equations to each element. Then combine and solve the equations.
Post-processing: Analyze and interpret the implications for the entire domain by calculating the results.
What are the Advantages of FEA?
Engineers face huge challenges when designing solutions that meet the changing needs of people and the planet. They rely on the flexibility of FEA to explore unlimited scenarios and conditions. With FEA it is possible to model any shape geometry (from a square block to a human heart), in any dimension (from nanoscale to a large passenger jet aircraft), with any type of physics (heat transfer, fluid dynamics, structural mechanics, etc.). Basically, as long as you have a partial differential equation, you can use FEA.
The advantages of FEA are the following:
Evaluate complex geometries: FEA can analyze complex structures that would otherwise be difficult or impossible to evaluate.
Simulate a range of physics: FEA allows engineers to model multiple physics problems simultaneously.
Save time, money and resources: FEA reduces the need for physical prototyping so engineers can evaluate the safety, reliability and performance of a design before its construction.
Challenges and Limitations of FEA
As with many technologies, the output is only as good as the input. FEA models depend on the accuracy of the information used to create them. All assumptions such as geometry, material properties and type of analysis can affect the integrity of the model's results. Only by feeding in the right data can FEA produce accurate insights.
Another challenge of FEA is that it must be used in collaboration with experts for best results. While FEA has become easier to use and AI promises to further democratize simulation, there is currently a need for proper guidance and safety measures to use FEA tools effectively.
Types of Finite Element Analysis Tests
Depending on the specific engineering problems being addressed, there are various types of tests that can be managed using FEA. Multi-purpose simulation software, such as Ansys Mechanical, provides a set of analysis tools to perform specific design scenarios. Here are some of the most common types of FEA testing:
Static analysis: Performed under constant loads where conditions will not change over time.
Dynamic analysis: Used in calculations involving time or frequency dependent variations.
Modal analysis: Looks at natural frequencies to predict how structures vibrate and how these vibrations can affect performance.