AN INTEGRATED CAD CAM SYSTEM FOR AUTOMATED COMPOSITE MANUFACTURE/

Fibre reinforced composites offer potential advantages to the aerospac e and automotive industries, including design flexibility, weight redu ction and reduced manufacturing costs. There exist two types of carbon fibre materials which are used to manufacture composites, resin-impre gnated ''pre-preg'' material and ''dry'' material. The later has an ad vantage of infinite shelf time as compared to the former. It therefore represents an increased area of interest. The current practice in ind ustry is to lay up pre-cut dry carbon fibre plies manually into the re quired component shape, referred to as preforms. The preforms are then placed into mould and high performance resin injected under vacuum. T he problem associated with this process is the high labour cost and lo ng manufacturing lead times required to lay up preforms manually. A mo re cost-effective approach is to lay up preforms automatically. This p aper describes an integrated CAD/CAM system for the automated manufact ure of dry carbon fibre preform structures. An automated preform lay-u p system, involving automated ply cutting, handling, lay-up, inspectio n and tacking, is described first, Process and task planning technique s are then proposed to generate the manufacturing data, required by th e lay-up system to lay-up a component, directly from the CAD file of t he component. This enables the lay-up system to be operated direct fro m CAD data. In addition, a vision system for the in-process inspection of preform stack against CAD specification is described and technique s proposed to facilitate the integration of CAD data with the vision s ystem. The performance of the preform manufacturing system is discusse d.