Graham Warwick/WASHINGTON DC
LOCKHEEDMARTIN is looking at simultaneously curing composite parts for the F-22 and Joint Strike Fighter (JSF) in one autoclave run, to reduce costs for both programmes. The procedure presents "-a unique opportunity for simultaneous cost reduction", the company says.
Batch curing of F-22 and JSF parts would be made possible by a processing-simulation program which has already saved more than $2 million on the production of composite components for the F-22, says Lockheed Martin Tactical Aircraft Systems.
The simulation tool, the COBRA (Code for Optimising Batch Runs in Autoclaves), models the curing of large parts and the co-curing of unitised composite structures.
Before it became available, optimisation of the curing process required physical testing in the autoclave, lasting up to two days and costing $3,000 per run. Using the simulation tool, autoclave curing can be optimised within 20min, at a cost of only $20, says the Fort Worth, Texas-based manufacturer.
The company says that it achieved a 98% acceptance rate on autoclaved parts for the first F-22.
A derivative of the COBRA cure-simulation tool, the Production Autoclave Leader (PAL), is being used to optimise the placement of parts and tools for curing.
Reducing assembly costs by combining composite parts into unitised structures increases the inter-relationship of the composite materials, tooling designs, curing environment and inspection complexity, the company says. "With these technologies-we believe we are positioned to successfully and affordably accomplish these challenges," says process-development centre manager Ken McKague.
Lockheed Martin has selected MacNeal-Schwendler (MSC) as a partner in its virtual product-development environment initiative, supplying computer-aided engineering software including structural-analysis tools and MSC's SuperModel integrated process-management, structural-simulation and analysis program.
Source: Flight International
