What is FEM (Finite Element Method)?
FEM is a numerical technique used to perform FEA (finite element analysis) of various physical phenomena.
This method is essential for solving complex engineering problems that involve partial differential equations, which are often difficult to solve analytically. FEM approximates these equations by discretizing the domain into smaller, finite elements, allowing for the analysis of complex geometries and material behaviors under various conditions.
To create a numerical model of a system or component, it’s necessary to make some simplifications. Things you only guess at aren’t important, and things you eliminate provide greater insight into what’s going on. And in structural mechanics, you’ll primarily eliminate the non-linear elements. You start with the assumption that doubling the load results in doubling the deflection, and that doubling the deflection results in doubling the stress level. Most FEM models are built based on these assumptions.
The issue with the grand assumption of linearity is that it simply doesn’t hold. Nothing is truly, completely linear. There are many cases where the linearity assumption is more than adequate to model performance and adequately determine safety and general suitability. But there are also cases where it isn’t, and further cases where forcing higher performance and efficiency based on the latest and greatest design variant requires a deeper understanding of the underlying physics and processes that determine how the thing actually behaves.
Nobody starts a non-linear analysis without a very good reason, but there are many good reasons to do so.
The role of FEM in digital engineering
FEM enables engineers to simulate and analyze complex systems. It allows for the precise modeling of structures, materials, and processes, facilitating the prediction of how products will behave under different conditions.
In civil engineering, for example, FEM is used to assess the structural integrity of buildings and bridges by simulating stress and strain distributions. In the automotive industry, it helps in designing safer vehicles by analyzing crash simulations. The method’s versatility extends to fields like biomedical engineering, where it aids in designing medical devices and prosthetics by simulating physiological conditions.
FEM accelerates the design process and reduces costs by reducing the need for physical prototypes. It allows engineers to explore innovative solutions and optimize designs before fabrication. This capability not only enhances efficiency but also improves safety by identifying potential issues early in the design phase.
What are the benefits of FEM?
FEM simulations offer tremendous support in the development process. They complement traditional component testing, which reflects the entirety and complexity of reality. Simulation allows tests to be conducted in virtual space that would be too costly or complex to set up in real-world testing. A major advantage is that virtually anything can be simulated on screen. The range of possible physical influences extends from mechanical force and temperature (differences) to electrical voltage and magnetic fields. The displacement of so-called nodes, which determine the individual elements, indicates the effects (such as deformations).
Model complex geometries
Simplify the modeling of complex shapes and irregular geometries, making it easier to analyze structures with intricate designs.
Adaptability
Can be adapted to meet specific accuracy requirements, reducing the need for multiple physical prototypes and allowing for rapid iterations during the design process.
Accuracy
Provide high accuracy in simulations, enabling precise predictions of how systems will react under various conditions.
Time-dependent simulation
Particularly useful for simulations that involve time-dependent behaviors, such as crash simulations or thermal analyses.
Visualization
Offer detailed visualizations that help engineers identify vulnerabilities in designs and make informed decisions on improvements.
What's the best way to get started with FEM in your organization?
For those new to FEM, starting with simpler models and gradually increasing complexity as familiarity with software tools grows is advisable. Engaging with training resources or consulting with experts can also accelerate learning. Keep reading to discover our recommended approach to FEM, or reach out to us for a free consultation today.
Use CAD software to design the geometry of the object or system to be analyzed. Ensure the model accurately represents the physical dimensions and features.
Assign material characteristics such as density, elasticity, and thermal conductivity. Use material libraries within the software or input custom properties as needed.
Specify constraints and loads that affect the model, such as fixed supports or applied forces. Define environmental conditions like temperature or pressure if relevant.
Divide the CAD model into smaller, finite elements (mesh). Choose appropriate element types and sizes to balance accuracy and computational efficiency. Refine the mesh in areas with expected high stress or complex geometry.
Determine whether a static, dynamic, thermal, or other type of analysis is needed. Use specialized FEM software to perform numerical analysis. The software calculates how each element behaves under specified conditions, solving equations iteratively. Check for convergence issues or errors during computation. Adjust settings or refine the mesh if necessary to ensure accurate results.
Use software tools to generate visual representations of data, such as stress distribution maps or deformation plots. Examine key metrics like maximum stress, displacement, or temperature gradients. Compare simulation results with experimental data or theoretical predictions to verify accuracy. Use insights gained from analysis to refine the design and improve performance.
Need help with FEM finite element method?
Johan Kolfors and team are on-hand to provide tailored guidance and support with a deep knowledge of the full Dassault Systèmes portfolio. Reach out for a free consultation today.
Essential software for FEM
Abaqus
For advanced engineering simulations and comprehensive analyses.
Isight
For predicting fatigue life and optimizing designs for durability.
fe-safe
For predicting fatigue life and optimizing designs for durability.
Simpack
For the analysis and design of complex mechanical and mechatronic systems.
View our extensive range of software solutions