Engineering vs. Composite Engineering

In our last articles, we were commenting on the lack of skills within the marketplace for composite engineering, due to the fact it’s not readily available through the higher education sector. This is obviously a topic close to a lot of your hearts, as we received more comments and responses from this article than we have for most of our others.

One kind reader asked a prominent question; “what defines a composite engineer”? At which point I thought it prudent to ask one of our newest recruits to Engineering to see how he is realising the difference. Here’s the outline of our quick chat – Jaffa Orange, Head of Engineering and Tim Gray, Design Engineer at Cecence Ltd.

What was life like before you joined Cecence?

Well, I used to work with large lumps of metal or plastic working them down into smaller pieces, by getting them forged, machined or bent to shape.

What did you see as your engineering role before?

The role was to take an idea, convert it into an initial concept via sketches, 3D models and calculations, then FEA, testing, prototyping, maybe 3D printing, plus cost analysis as required, a review against the specification, would lead to engineering drawings, assembly instructions and CNC data to allow manufacturing. These were a typical set of activities within my previous sectors, marine equipment for commercial and superyachts, underwater remotely operated vehicles (ROVs) and architectural projects.

What’s the difference now in composite engineering?

Straight off, the difference is the materials. Composite materials just behave completely differently to the plastics and metals. Then there are some different processes in both the design stages and manufacturing.

How are the materials different

When working in metals, the properties are pretty much the same in all directions, these can be manipulated slightly but they are typically isotropic. Composites on the other hand are made up of complex selection of fibres in a resin matrix. Rendering it anisotropic, where the properties differ in different directions, these depend on:

• Fibre type
• Fibre weave
• Resin
• Number of fibre layers
• Fibre angle
• Layup method

Understanding the material properties and the resin systems and how to apply them is key. The main difference is unless it’s a very simple prepared lump of composite, you’re making the component as you go along, creating properties as you make up the laminate where the processing also has an effect. The variables are HUGE and there are many constraints.

Is there a go-to source of information?

Well, in metallics, there are large data sets for the properties that are exhibited in various circumstances. A lot of CAD systems have typical material libraries included in the package, but they are biased towards metals and plastics. However, such tools are simply not so readily available in the composite world. The number of fibre and resins are eever-increasing and although there’s data available for each of these, you can’t simply pick a number for the overall laminate off a single layer datasheet, its a complex build up of different layers with varying properties. Cecence’s composite material library is pretty comprehensive and ever increasing, which allows us to have greater confidence and put more intelligence into the design process.

Does this mean that every composite project must go through a learning curve?

Well almost. However, if you find an organisation that is consistently working in composites and pushing R&D in material development and processing, they will already have a head start against a traditional engineering firm used to metals and plastics. They’ve been through the hardest learning curves, and while there will still be many iterations required, the overall process will be faster with their learnings and best practice experience to date.

Do you see a different approach at Cecence?

At Cecence we are always trying to develop the best selection of materials for the given project, while taking care to ensure that the end result is repeatable at scale, in a timely and cost-effective manner while also producing a superior part.

When I originally joined, we were R&D focused and optimising the engineering, however, we have rapidly grown into a full competency house, with our core focus being on the production capability, with an in-house engineering team on hand.

We have created our own data sheets in specific areas and have also seen a pattern as to where most composite projects require the most help. That has led us to start to look at our service portfolio and see where we can offer a fixed price, fixed scope service to help our clients along the TRL pathway considering us as composite consulting and optimisation partners along the way. But what is really great is to be working alongside the production team and actually seeing the project design iterations come out in production.