FEA keeps RPC on track

MARK Harrison, engineering manager with RPC Technologies based in Newcastle, NSW, is not sure how the company would operate without FEA technology.

MARK Harrison, engineering manager with RPC Technologies based in Newcastle, NSW, is not sure how the company would operate without FEA (Finite Element Analysis) technology.

“In our kind of work, FEA is essential,” Harrison told Manufacturers Monthly.

RPC has two engineering offices and four manufacturing plants. “Here (Newcastle) is the main engineering office for RPC’s ‘Transport’ division with Seven Hills (Sydney) the main engineering office for RPC’s ‘Industrial’ division. We transfer FEA files between the two sites as the workload dictates.

“We do the stress analysis for the pipe work for desalination plants, odour control systems, mining intakes and ducting, water intakes for power plants. And we’re talking big pipes; some of them are two and three metres in diameter.

“We also do a lot on the transport side; train seats, lights, linings and external composite paneling etc to customer specifications. Our major customers include United Group Rail, Evans Deakin Industries and Bombardier.

“We design a whole range of seats; fixed, reversible and flip up seats, all designed to take fairly extreme loads. They’ve got to withstand 5G longitudinal, 2G vertical, and 2G lateral loads as well as a whole range of other ‘vandalism’ loads.

“We also do the canopies (or masks), for example, on the fronts of trains which are designed to take ballistic impact loads of besa blocks and similar objects. We also design ballistic protection systems for the defence industry.

Harrison says the company uses FEA to refine the design and then later testing validates the results. The company uses NX Nastran (version 4) for FEA, Femap (version 9.3) as the user interface, and a SolidWorks 2007 CAD system.

“We exchange a lot of our customers’ information through SolidWorks. That way we’ve got a closer interface with them,” Harrison said.

While Nastran is not integrated with SolidWorks, Harrison say it’s not a problem. “It’s a straight translation. You simply mesh your model, put in your loads and boundary conditions and run your analysis.

With today’s train and vehicle seats more likely to be designed to absorb energy instead of just being rigid, Harrison says FEA is playing a greater role than just reducing mass.

“Now if a passenger is flung into a seat, the seat will fail in such a way as to minimise the damage to the person as opposed to sitting in something that’s just rigid and hard.”

Harrison says these changes mean more complicated designs. “We’ll go through mock ups but it usually takes between a year and 18 months to design a seat from fresh air. All the way through we’re analysing things.

When it comes to FEA, Harrison says he is finding customers are now more demanding.

“They’re asking for 3D models of everything. Every single component of a train is 3D modelled. We are able to give the mass, the weight and we’re able to analyse the stresses.

“We’ve got dynamic programs where we’re able to see where all of the stresses are. That gives us a massive start when we start to prototype, which is the way we validate our design.

“As well as reducing mass, the other big driver, particularly in the transport industry, is fire retardancy.

“We are always looking for materials that don’t burn, aren’t toxic, etc, etc. We use a lot of composites in our design.”

Harrison says by being able to offer this sort of service to customers puts the company ahead of its competitors, “especially where strength and the ability to reduce mass, stress and strain is important”.

“FEA is great marketing tool to help you win the job. You’re also a long way ahead of the game,” Harrison said.