Aircraft without Rivets - Laser Welding Makes the Impossible Possible

This paper explores the innovative Laser In-situ Joining (CONTIjoin) process developed by Fraunhofer IWS for the longitudinal seams of fuselage shells made of carbon fiber-reinforced thermoplastic (CFRTP), based on a continuous co-consolidation of CFRTP laminates. In contrast to adhesively bonded connections, CONTIjoin does not require elaborate pre-treatment and only necessitates a clean surface to ensure a proper bond. The inclusion of mechanical fasteners such as rivets can be avoided, being beneficial for the structural integrity of the aircraft and overall weight. The CONTIjoin process, with its unique combination of CO2 laser technology and high-speed scanning, represents a promising advancement in continuous co-consolidation techniques for CFRTP butt straps, offering an efficient alternative to conventional methods. The precise temperature control mechanism ensures homogeneity and quality in the resulting co-consolidated joints. The welded connections achieve over 90% of the strength level of the static heat-pressed base material of the fuselage shells.