What is finite element analysis and what is it used for?


Finite element analysis (FEA) is the modeling of products and systems in a virtual environment to find and solve potential structural or performance problems. When we talk about FEA we have to know that it is the finite element method (FEM) in practice to mathematically model and numerically solve challenging structural, fluid, and multiphysics issues. FEA software can be used in a wide range of industries but is commonly used in the aeronautics, biomechanics, and automotive industries.

A finite element (FE) model consists of a system of points, called “nodes”, which draw the shape of the design. Connected to these nodes are the finite elements themselves, which make up the finite element mesh and contain the structural and material properties of the model that define how the model will respond to certain conditions. The density of the finite element mesh can vary throughout the material, depending on the anticipated change in stress levels in a given area. Regions that experience significant changes in stress typically require a higher mesh density than those that experience little or no change in stress. Points of interest include fracture points in a previously tested material, curves, corners, complex details, and areas of high stress.

Creating Finite Element Models

By using beams and shells instead of solid elements, a representative element can be created using fewer nodes without sacrificing accuracy. Each modeling scheme requires the definition of a different set of properties, such as section areas, plate thickness, moments of inertia, bending stiffness, torsional constant, and transverse shear.

[H2]Simulation of real-world working environments

To simulate the effect of real-world working environments on the FEA, several types of loading can be applied to the FE model, including nodal loads (forces, moments, displacements, velocities, accelerations, temperature, and heat flow), elemental loads (distributed load, pressure, temperature and heat flow), as well as accelerating body (gravity) loads.

Types of FE analysis include linear statistics, static and nonlinear dynamics, normal modes, dynamic response, buckling, and heat transfer. Typical results calculated by the solver include nodal displacements, velocities, and accelerations, as well as elementary forces, deformations, and stresses.

Advantages of FEA

 FEA can be used in a new product design or to refine an existing product to ensure that the design can conform to specifications before manufacturing. With FEA you can:

  • Predict and improve product performance and reliability.
  • Reduce physical prototypes and testing.
  • Evaluate different designs and materials.
  • Optimize designs and reduce material usage.

How does Finite Element Analysis work?

 The geometry of the component is separated into “elements” that reflect the continuous domain of the issue and are subject to loads and restrictions. Dividing the geometry into small elements solves a complex problem by subdividing it into simpler problems, allowing the computer to perform tasks efficiently.

 The technique suggests substituting a limited number of elements of well-defined behavior for an unlimited number of unknown variables. Depending on the nature and scope of the issue, these divisions may be triangular, quadrangular, or in various configurations. As the number of elements is limited, they are called “finite elements” – the word that gives a name to the method.

 The finite elements are connected by points, which are called nodes or nodal points. The set of all these items – elements and nodes – is called a mesh. The accuracy of the Finite Element Methods depends on the number of nodes and elements, the size, and the types of elements in the mesh. Therefore, the smaller the size and the greater the number of elements in a mesh, the more accurate the analysis results will be.

 Computational simulation software keeps evolving and improving method-based analyses, promoting the improvement of element type selection and mesh generation, modeling techniques, acceptance criteria, errors, and presentation of results, allowing easier use of the tools. Therefore, the knowledge of the fundamentals of the method is necessary to develop, together with the software mastery in Autodesk Inventor, the best methods for utilizing this valuable resource in the creation and assessment of projects and products.