Production of a complex shape thermoplastic CFRP structure by T-AFP with in-situ consolidation

This paper reports the experimental research conducted to access the feasibility and quality of a thermoplastic CFRP structure manufactured by means of a laser-assisted thermoplastic automated fiber placement (T-AFP) process. The structure geometry consisted of a 10 mm radius and surface undulations with 10 mm amplitude. The focus of this study was on the radius area, as well as layup regions adjacents to the radius. A range of samples with constant stacking sequence and varying processing parameters (tow count, layup speed, compaction force and repassing strategies) were manufactured. The local quality of the radius was analyzed by optical microscopy, DSC, and curved beam strength according to ASTM D 6415. A correlation between processing conditions and laminate quality could be determined. Good laminate quality could be achieved on the flat regions according to in-situ metrics, but higher porosity and local variations in the laminate quality were observed in the corner region.