Fabrication of a thermoplastic matrix composite stiffened panel by induction welding

In this work, the experimental and numerical study of induction welding devoted to the fabrication of a composite stiffened panel, representative of a typical aeronautic sub-component, is presented. A thermoplastic matrix composite, polyphenylene sulfide (PPS) reinforced with carbon fibers, is used. The influence of the fundamental process parameters, such as generator power, distance between induction coil and laminate, coil geometry and laminate lay-up on the heating rate and the heat distribution was analyzed applying finite element simulations. The model was validated through the comparison of experimental and model results obtained in static experiments. Optimized parameters for composites welding were found out, and the mechanical properties of the welded joints were evaluated by single lap shear and pull-off experiments. Finally, a prototype panel made of a flat laminate stiffened with four “L” shaped stringers is fabricated by continuous induction welding, exploiting modeling and experimental results. A C-scan of the panel was also performed.