What is Finite Element Analysis (FEA) and Why Use It?

By 29 October 2019 News No Comments
Haughton Design FEA

Why use FEA?

When designing a new product, having the ability to make prototypes is ideal as it means issues can be found early in the process. However, not all projects have this luxury so must be right first time – a challenge we’re used to seeing. Many of the projects we deliver must be right first time, whilst incorporating challenging mechanisms and structures, plus a variety of materials. So how do we overcome this challenge?

We use computer simulation to model load cases throughout all design and development projects. It’s an iterative process to create concept designs, run FEA scenarios, then develop and optimise the design for maximum performance.

Here’s a quick explanation of the different types of analysis that can be utilised:

Linear & Non-Linear FEA

Materials can either be linear elastic (where the relationship between stress and strain in the material is linear – for example aluminium or steel), or non-linear elastic (where the relationship between stress and strain in the material is non-linear – for example, polymers). Linear elastic materials are typically linear elastic up to a point, and then start displaying non-linear elastic behaviour.

Linear FEA is carried out when a part is made from a linear elastic material, and there is not much deformation caused by the forces being applied to the part. Where the material is non-linear elastic or the forces being applied can cause large displacements, a non-linear FEA must be performed.

Static FEA:

A linear static FEA is performed when the forces applied to a part or assembly do not change over time. A static FEA is the simplest form of FEA, and is performed exclusively on linear elastic materials, where small displacements are anticipated.

Dynamic FEA:

A dynamic analysis is performed when the forces applied to a part or assembly change over time. A dynamic analysis can be performed on either linear elastic or non-linear elastic materials. Common examples of a dynamic study include drop tests and vibration analysis.

CFD – Computational Fluid Dynamics:

CFD simulates how gasses or liquids flow in, or around, a part or assembly.

Thermal Analysis:

Thermal analysis simulates heat transfer between solid bodies. A thermal analysis can be a useful standalone tool, for example when analysing the design of a heat-sink. It can also used in combination with a static analysis to conduct thermal stress analyses on parts or assemblies.

Using FEA can be hugely beneficial to a project as it can reduce costs, save time and improve product performance. Further benefits arise with lower environmental impact by using reduced material usage for optimised rigidity/flexibility/weight. Effective use of FEA throughout the process will ultimately ensure your design is fit for purpose.

One of the biggest issues we find with FEA being outsourced, is that the iterative nature of design optimisation can be broken or come too late. The truth is that it’s typical for analysis to identify issues in a design, which subsequently require further investigation and design optimisation. Therefore, it is always an advantage to introduce FEA, as early as possible, into the design process. This means problems are identified more quickly and changes can be made to the basic design early on. Doing this well before extensive engineering is undertaken will significantly reduce time and therefore costs or delays.

If you need any advice or guidance on the effective use of FEA to speed up your product development process, please get in touch and we will be glad to help.