Abstract

In-situ fiber placement, in combination with automated tape laying and filament winding, is the key to high-volume production of large-scale composite aerostructures ranging from simple flat plates, to panels with mild curvatures, to complex three-dimensional surfaces, promising reliable, consistent and cost-effective fabrication. However, manufacturing cost, slit tape quality, lack of knowledge and experience of the in-situ consolidation fiber placement process are major barriers preventing aircraft manufacturer from implementing this unique processing technique. This dissertation aims to gain knowledge and experience of in-situ consolidation fiber placement by identifying and resolving four technical issues associated with the manufacturing of thermoplastic composite tailbooms. The first study demonstrates that the percentage of gap/lap and the angular deviation of fiber orientation can be controlled by dividing a single tool surface to multiple and equal sections. The second study shows that the interlaminar defects have minimal effects on the mechanical properties of autoclave molded thermoplastic composite laminates. The third study predicates a set of optimum processing parameters for manufacturing tailboom demonstration articles using automated fiber placement. The last study suggests that the in-situ consolidation fiber placement process needs to be improved to lower the micro-size void content and minimize the process induced warpage.