Automating lay-up of composite aerospace components

Citation

(1999), "Automating lay-up of composite aerospace components", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 5. https://doi.org/10.1108/aeat.1999.12771eab.009

Automating lay-up of composite aerospace components

Automating lay-up of composite aerospace components

Keywords: Composites, Cincinnati Machine, Aircraft, Satellites, Fibre

Cincinnati Machine has received an order from Construcciones Aeronauticas, SA (CASA), Madrid, Spain, for a seven-axis Viper 3000 Fiber Placement System (FPS) (Plate 1) enabling automated lay-up of large, complex geometry, composite structures. The first FPS for the European community, the Viper 3000 will be used by CASA to produce composite components for the Ariane 5 rocket launcher and other satellite and aircraft programs.

Plate 1 Possibly the most complex computer-controlled machine used anywhere in the industry, the Viper 3000 Fiber Placement System from Cincinnati Machine

The largest Viper system produced yet by Cincinnati Machine, CASA's FPS will permit independent dispensing and control of 32 separate ÷in. (3.2mm) fiber tows, up from 24 tows on previous machines, said Ron Hennies, composites product manager for Cincinnati Machine. This allows a lay-up bandwidth of 4in. (102mm), compared to 3in. (76mm) previously, to shorten lay-up time.

CASA currently uses three Cincinnati Machine composite Tape Layers as a key European supplier of composite aircraft components, particularly for the Airbus program. Scheduled for installation in the second half of 2000, the new Viper gives CASA the most comprehensive capabilities at composite fabrication in the European aerospace community, said Hennies. The Tape Layers are particularly suited to large, low contour surfaces, such as wings and tail structures, he noted. The Viper, by contrast, enables automated "in the round" fabrication of highly contoured 3-D structures such as aeroplane fuselages, jet engine cowls, rocket case sections and engine inlet ducts.

The Viper FPS combines the advantages of filament winding, contour tape laying, and computer control to automate production of complex parts that conventionally require extensive hand lay-up, said Hennies. Precision fibre placement serves four key improvement objectives for aerospace manufacturers, he added - reducing costs, cycle times, structural weight, and handwork/rework.

"Automated fabrication greatly expands the advantages possible with composites", said Hennies. "On top of the proven weight savings offered by high-strength composites, our CNC systems allow one-step production of large monolithic structures". This can greatly reduce part counts, assembly operations, and overall purchasing and manufacturing logistics, he stressed. Since parts are made to near net shape, subsequent machining and material waste are reduced for lower total cost.

Seven-axis capability - particularly a three-axis "wrist" - lets the Viper FPS steer fiber tows to create shapes and geometries, while maintaining desired fiber angles for maximising part strength and minimising part weight. Each of the 32 tows can be independently dispensed, clamped, cut and restarted for uniform lay-up over curved, convex or concave and compound contoured surfaces without wrinkles or bunching. The machine can place fibre tows at speeds of up to 1,200in. (30m) per minute with accuracy to þ0.050in. (þ1.3mm). Start/stop tow control enables creation of precision openings for windows, doors and hatches, minimising need for subsequent trimming and hand finishing.

CASA's Viper 3000 FPS will have 52.5ft (16m) of horizontal Z-axis (carriage) travel and 5ft (1.5m) of X axis (front/back) travel. The tows are placed on mandrels that rotate in a horizontal axis. Two mandrel stations can each handle part diameters up to a maximum of 18ft (5.5m).

Besides the Viper 3000, Cincinnati Machine in 1998 introduced a new compact, low cost version of the FPS, the Viper 1200. Designed for computer-controlled fibre placement of smaller, highly contoured composite parts, the compact Viper 1200 provides the same seven-axis dexterity, said Hennies, but with a 12 tow-head, minimum Z-axis travel of 15ft (4.6m) X-axis travel of 5ft (1.5m) and maximum part diameters of approximately 6ft (1.8m).

Advanced Cincinnati controls and software, designed specifically for composite processing, are said to make it easy to program and control Viper multi-axis movements for lay-up of complex geometries, said Hennies. Proprietary Acraplace programming software translates CAD tooling and part data into seven-axis commands, developing the paths and tool rotations for applying the composite materials to curved and geometric surfaces while keeping the compaction roller normal to the surface. A simulator module confirms the part program with 3D animation, while integrated collision avoidance post-processing of the NC program automatically detects interferences.

Further details are available from Cincinnati Machine. Tel: +1 513/841 7881; Fax: +1 513/841 8306. Visit Cincinnati Machine's homepage at , www.cinmach.com