GKN Aerospace use Umeco’s composite tooling mandrels for manufacture of Airbus A350XWB wing spars.
Umeco manufactured a suite of large-scale tooling mandrels for GKN Aerospace using their tooling prepregs and GKN now uses these tools to produce Airbus A350 XWB rear wing spars using advanced fibre-placement (AFP) technology.
According to Umeco officials, they were asked by GKN to design and manufacture low-weight, low-cost mandrels exhibiting high stiffness and excellent geometric accuracy (essential requirements due to a maximum permissible 2mm deflection allowance at the mandrel mid-point).
Umeco explain that the mandrels consisted of machined foam cores over-laminated with their LTM217 epoxy tooling resin system combined with woven carbon fibre and ultra-high modulus unidirectional carbon fibres. The mandrels were then machined in their assembled state to the final spar dimensions, within the specified ±0.25mm tolerance. They say the suite of tooling mandrels (measuring 13.7m, 12m and 11.9m) provide GKN Aerospace with undeniable benefits:
The designs incorporate a vacuum system to facilitate air extraction at the debulking stage from a single point at the end of each mandrel. This leaves the full length of the mandrel surface uncluttered and accessible for the AFP operation, while simplifying the vacuum bagging operation.
Initially designed specifically for current Airbus A350 XWB wing construction, all four mandrels can be re-machined and re-laminated to implement quickly and cost-efficiently geometry changes.
Liam Moloney, Umeco engineering manager – Tooling, states “We were pleased by the prospect of working with GKN Aerospace and applying our tooling expertise and prepregs on a project of this magnitude. These tooling mandrels set a new challenge for us, but we rose to the occasion and succeeded, both for us and also for our customer. The tooling mandrels are now being used to manufacture wing spars for aircraft which are setting the standards in aviation.”