Design of thermoplastic composite manufacturing withautomated fiber placement towards in-situ consolidation

The increasing demand for lightweight, high-performance materials in the aerospacesector has driven the evolution of advanced manufacturing techniques for thermoplasticcomposites. This thesis focuses on the design and optimization of thermoplasticcomposite manufacturing using Automated Fiber Placement (AFP) with an emphasis onin-situ consolidation. A systematic approach is undertaken to address the challengesassociated with the AFP process, including temperature distribution, degree of intimatecontact, interlaminar bonding, and multi-scale permeability.The research employs a combination of experimental and numerical methods to evaluateand enhance the thermal and mechanical performance of carbonfiber/polyetherketoneketone (CF/PEKK) composites. Key studies include thedevelopment and validation of thermal models incorporating thermal contact resistanceto predict temperature histories during layup. Experimental investigations quantify theeffects of fiber orientation and layup speed on the degree of intimate contact andinterlaminar bonding strength. Novel correction factors for bonding prediction modelsare introduced to improve the accuracy of process outcomes. Results reveal that optimized thermal and mechanical conditions significantly improvebonding quality and reduce void formation. Multi-scale permeability analysis usingpulse-decay and micro-computed tomography methods highlights the interplay betweenprocess parameters and microstructural properties. The findings contribute to the broaderunderstanding of AFP process dynamics, paving the way for sustainable, efficientmanufacturing of high-performance thermoplastic composites.The study concludes with recommendations for process optimization and avenues forfuture research to further enhance the application of AFP in thermoplastic compositeproduction. This work provides a comprehensive framework for integrating advancedmanufacturing techniques with materials science to meet industry requirements.