CompositesWorld
Issue link: https://cw.epubxp.com/i/944580
NEWS 39 CompositesWorld.com director Dimitar Bogdanoski. "We have processed multiple TPC tape products, including those from Barrday, TenCate, Toho Tenax and Suprem." e machine can lay four or eight tapes/tows. "Any of the tows/ tapes can be cut if you don't need all of them placed," says Bogda- noski, who claims an automated head change, from ATL to AFP (or vice versa) can be completed in 5 minutes. "AFP has a lower scrap rate vs. ATL due to the narrower material, so it is increasingly preferred. It's useful to have this change capability to define which process is better for your part or project." Changing from thermoset to TPC takes about an hour, swapping the infrared (IR) heater used with thermoset materials to a 3-, 4- or 6-kW laser used with TPC — depending on the width of material that will be placed. "We can even use a 12-kW laser, but it requires a special license," Bogdanoski notes. "e machine speed is between 5 m/min and 30 m/min for ISC parts, regardless if the material is PPS, PEEK or PEKK. We use an IR camera and an in-house developed thermal model, which forms a closed loop to control temperature of the laminate. It also incorporates video monitoring, which we developed in-house for quality assurance." MIKROSAM sold one of these systems in 2016 and three in 2017. TPC parts produced on Coriolis machines now benefit from what the company calls a "closed simulation chain," which inte- grates computer aided design, manufacturing and engineering (CAD-CAM-CAE) enabled by the company's bidirectional software interface and integration (Fig. 3, p. 37). "e part begins with design by the OEM in CATIA [Dassault Systèmes, Velizy-Villacou- blay, France]," says Hamlyn. "Our CAT/CADFiber software imports the composite stacking from CATIA and gives the user the tools needed to model all of the fibers. It then generates and optimizes the AFP tape/tow courses." After a test part is placed for validation, the software then exports true "as-built" fiber angles — including singularities such as tow drops and gaps due to use of narrow tapes, etc. — to commercial FEA solvers (e.g., NASTRAN, ABAQUS, SAMCEF) and enables mesh mapping between the AFP surface and the struc- tural FEM mesh. Hamlyn says this reduces errors and facilitates data transfer as well as modeling of forming simulations. "is is the first step towards automating design optimization," he asserts. "So now designers can perform structural analyses and crash simulations, interfacing with ANSYS [Canonsburg, PA, US]." e latter uses solid modeling instead of FEA shell elements for simu- lation of multi-ply composite laminates. Next, physics-based FEM draping/forming simulations are performed, using programs like AniForm (Enschede, Nether- lands) or ESI Group's (Paris, France) PAM-FORM. "is includes intra-ply shear and fiber loading during forming, compaction and ply-ply slip," notes Hamlyn. us, issues with wrinkles, gaps and fiber orientation during the transformation from 2D layup to 3D preform or part can be addressed and the preform contour can be optimized. He continues: "You then compare simulation results to real part trials to validate what is really happening. Once the design is frozen, our software interfaces with Dassault Systèmes' DELMIA for machine simulation to check laying metrics and robot ISC of TPCs, Part 1 movements, ensuring that the AFP head can produce the part without collisions, etc. Once this is okay, our post-processor will transform the digital design into robot code, so the AFP machine will do exactly what you have simulated." "Factory of the Future" is digital design and manufacturing chain and the automation already proven in large TPC aerostructure demonstrators align well with the Clean Sky 2 vision for future aircraft manufacturing, which is described as highly automated, flexible and based on functional integrated design. ermoplastics also offer a means for attaining a multifunctional airframe, especially as the line between AFP and 3D printing dissolves. Clean Sky 2's Platform 2 "Innova- tive Physical Integration Cabin – System – Structure" program includes large, integrated fuselage demonstrators. e Clean Sky 2 Joint Proposal Platform 2 key drivers are cost and weight: "Without considering the engines, more than 50% of the recurring cost of manufacturing an aircraft is deter- mined by the fuselage, the cabin and cargo equipment and the integration effort performed in the assembly of these components. .… considering a short-range commercial aircraft operating over 15 years, the reduc- tion of just 100 kg of its original weight leads to more than 4 tons of fuel saving. Therefore, the potential of lighter and more efficient structures and systems for contributing to the ACARE vision 2020 [50% cut in CO 2 emissions, which means 50% cut in fuel consumption for new aircraft in 2020], is enormous." By combining multiple airframe components into a much smaller number of integrated, TPC-based modules equipped with distributed power and systems, myriad parts, fasteners and holes are eliminated with a corresponding cut in machining and assembly operations. Clean Sky 2 proposes that potential weight savings could provide up to a double-digit reduction in fuel burn and a sustainable path to meeting future aircraft demand. Although there is still much to be developed and validated, ther- moplastic composites seem destined to play a part in the aircraft factory of the future. In Part 2, CW will explore issues with PEEK and PEKK mate- rials and quality of tapes as well as the debate over a one-step vs. two-step process, all of which will impact how in-situ consolidation and thermoplastic composites play a part in future aircraft. CW senior editor Ginger Gardiner has an engineering/ma- terials background and more than 20 years of experience in the composites industry. ginger@compositesworld.com