Continued...
The consultancy then used software written inside their Catia v5 CAD system to trim this point count to a few thousand each, again incorporating a repetitive check routine to ensure that even though the point count was being reduced significantly, none of the surface accuracy was lost.
Once completed, an independent check of the CAD representation of the wing skin surfaces was undertaken in order to compare them with the original design intent, before Bennetts translated them into actual tooling designs.
As well as meeting all the requirements for accuracy inherent in this project, two other important factors had to be taken into account in the tooling designs. First, the tool shapes had to be rapidly adjustable to allow for product life-cycle changes. Conventional tooling methods used for components of this size are generally not able to be adjusted or adapted. Second, the tool surfaces had to be able to carry the high loads exerted by the pressure involved in the process.
The alternative tooling concept developed by the project team involved a thin plate formed over relatively tightly spaced laser-profiled rib boards. The vacuum would then be used to pull the plate to shape on each forming cycle, with the strength of the aluminium panel combining with that of the intermediate plate to hold the correct shape throughout the forming process.
Delivering a panel to the creep forming tool
Wrapping a wing skin and tool before creep forming in the autoclave
