What are claimed to be the lightest composite armour plates on the market have been produced with the help of a new highly-advanced computer modelling program that works like finite element analysis, but inversely.
Armor Designs, a US manufacturer of composite armour products, has patented the program, called Volumetrically Controlled Manufacture (VCM) for rapid design and manufacturing of advanced composite materials. The technology has already caught the attention of top government clients.
The company recently used VCM to develop 1.5kg composite armour plates, which are claimed to be the lightest on the market, for the US National Institute of Justice to use on its vehicles.
Dave Seaton, chief financial officer of Armor Designs, explained that with finite element analysis the strength of a material is the unknown factor, but with VCM and inverse finite element analysis the unknown factor is the original material.
‘With finite element analysis you have a known product, like a lump of concrete, and you’re trying to find the strength of that lump of concrete,’ he said. ‘So you put it under a known force in a press and turn on the pressure. When the concrete crumbles you know how strong it is.’
Conversely, with inverse finite element analysis the manufacturer knows the force that needs to be put on a material and how strong the material has to be to do the job. ‘Our VCM program will come out with a solution with what the material has to be made of,’ said Seaton.
The system was invented by Armor Designs founder James St Ville, and runs on millions of algorithms that were developed during more than a decade of research.
Seaton said it was the VCM program that gave his company ‘the recipe’ to produce the lightweight composite armour plates for the Institute of Justice. After feeding in all the minimum strength requirements, the program checks against a database of material properties and tells the company the material required, the optimum number of layers, the amount of time required for curing and the pressure required to compact the composite material. ‘Inverse finite element analysis and VCM allows you to come up with a solution that will reduce the weight required in the material, but not at the expense of the strength of the material,’ said Seaton.
The composite armour plates to be used on the Institute of Justice’s vehicles are expected to slash the weight of the cars. ‘Traditionally, armoured vehicle plates are made of steel,’ said Seaton. ‘Reinforced armour-plated steel is incredibly heavy and unstable in terms of the centre of gravity, so it is not very easy to drive.’
Seaton said Armor Designs’ research team has also been considering how composite armour could have dramatic effects on the weight of aircraft.
‘We worked out if you re-armoured a Chinook twin prop helicopter with our composite plates you could take 2.5 tonnes to 3 tonnes of weight out,’ he said. ‘You would have less drain on the engines, less wear and tear on the chassis, the air frames and so forth.’
Armor Designs has recently expanded its research and development team at its US headquarters in a project known as Scorpion Works. The aim of the research is to find more commercial applications for the company’s VCM technology by reviewing products that could possibly be made better and more easily.
‘There are some products out there that are completely over-engineered and rather impractical to manufacture,’ said Seaton. ‘We want to make sure that isn’t the case in anything we do.’
Advanced computer modelling program can help produce lighter armour plate but not at the expense of strength, claims developer. Siobhan Wagner reports.