2D Fiber Placement of Integral Thermoplastic Frame Structures

State-of-the-art aircraft frames are built with thermoset resin systems necessitating time and cost-consuming autoclave curing cycles. The substitution of these materials by unidirectional tapes with thermoplastic matrices offers potential to use out-of-autoclave, highly automated and therefore cost-efficient manufacturing technology. Within a collaborative research, the manufacturing of highly integrated frame structures using laser-assisted automated fiber placement combined with stamp forming and co-consolidation to develop a cost- and time-efficient process chain has been investigated. This study mainly presents the investigation results of the laser-assisted fiber placement process including manufacturing engineering investigations regarding guide curve design as well as the effect of variable angle guide curves on the mechanical properties. Therefore, various guide curve geometries have been investigated and resulting fiber angle deviations as well as cover ratios analyzed. In addition, coupon laminates with straight and curved fiber paths have been manufactured and tensile testing done.