A holistic assessment of a stiffened panel production using a novel thermoplastic material and implementing the induction welding process

Purpose The purpose of this paper is to investigate the feasibility to produce a novel aircraft full stiffened panel using entirely a new hybrid thermoplastic composite material allowing for appreciably lower processing temperatures as compared to conventional structural thermoplastic composites. Design/methodology/approach For stiffening the fuselage skin panel, the out of autoclave welding of four composite stringers was obtained using a modified induction welding (IW) process. The quality of the welds was investigated using micro-tomography and the mechanical strength of the lap joints was assessed by means of single-lap shear strength (SLSS) tests. Moreover, a holistic design index was implemented as a decision support tool for selecting the optimal set of IW process parameters. Based on the index used, the quality as well as the entire life cycle cost and environmental impact are accounted for. Findings Low porosity values as well as no deconsolidation were observed at the investigated application, and the average measured SLSS, even found lower, lies within the range of the respective values encountered in other similar high-performance applications. It is exhibited that after the optimization, the IW process offers significant potential to replace the autoclave process in welding applications. Thus, it paves the way for reduced cost and increased sustainability, while still meeting the predefined quality constraints. Originality/value Although several studies on the IW application have been conducted, limited results exist by using novel thermoplastic materials for aircraft structural applications.