The technological base of the project is an AFP machine capable for in situ consolidation installed in 2012 at TUM and supplied by AFPT GmbH
INSCAPE implements the demands of the aerospace industry with additional requirements in terms of quality, productivity, flexibility and intensive use of full 3D placement as well as the integration of subcomponents like thermoformed stiffeners and spars.
Project activities:
• Developments on machine hardware
• Design work related to the demonstration hardware
• Material and Process development, process demonstration as well as material performance characterization
These activities correlate with the project partners experience whereby the AFPT GmbH is focused on machine hardware development and machine code generation, FACC AG as composite component supplier to the large aircraft manufactures, concentrate on demonstrator and tool design. The scientific partners put emphasis on the material and process development topics.
Operation on 3D curved panels as well as improved performance and improved contour accurate layup required a higher complexity compared to the existing single tow head design. Two development trajectories were driven: A new head design for new hardware and a technology prove by modification of the existing hardware.
The component design was performed within CATIA Composite Design for laminate definition, but transfer to an offline machine programming environment is limited. There’s no consistency between CAD and CAM. Individual approaches were required to enable the demonstrator manufacturing. An adapted version of CGTech VERICUT software is used for 3D offline programming the skin placement code.
Even the main manufacturing stream of INSCAPE is based on AFPisc processing, two alternative routes had to be prepared by TUM for stringer manufacturing. The interaction of both processing routes were proved within the manufacturing and demonstration activities.
The demonstrator manufacturing has revealed major influences of the solid aluminium tool. Big difference in heat transfer properties between mould and carbon fiber laminate (stiffener profiles) requires specific control strategies for the AFPisc process. Typically controlled by a closed loop control, no predictive actions can be performed. But this is a requirement for the in situ joining process. Therefore hard coding of machine parameters linked to position information had to introduced for advanced demonstrator manufacturing.
PEEK and PEKK based CF tapes were investigated for their processability. Fiber and resin distribution as well as homogenity and resin flow behaviour are critical characteristics for AFPisc.
Project partner INEGI performed an intensive material characterization program, based on panels produced with the demonstrator manufacturing setup. The mechanical performance could not fulfill the high expecations for aerospace use. Insufficent interface creation, indicated by porosities, are assumed to be a major reason. The optimization of the tape material for use in the AFPisc process is one recommendation. The optimziation of processing parameters are the second topic to close the gap to an aerospace quality level.
