Optimization of Automated Fiber/Tape Placement Technology for High-Performance Thermoplastic Composites

Abstract

Nowadays, Automated Fiber/Tape Placement Technology (AFP) has gained a huge interest especially for High-Performance Thermoplastic Composites, replacing the manual hand layup. It offers high automation, productivity, and structure complexity, particularly for aerospace and automotive applications. While AFP with thermosets achieves high consolidation, challenges persist with thermoplastics, including void formation and uneven consolidation, necessitating post-processing like thermoforming. Thermoforming enhances the quality of the AFP laminate by reducing voids and defects, which is crucial for maintaining optimal mechanical properties and preventing issues and difficulties, such as local thickening. Three experimental scenarios were explored, including hand tape layup followed by thermoforming, AFP with in-situ consolidation without post-processing, and AFP with in-situ consolidation followed by thermoforming. The research focuses on optimizing the promising AFP technology for high-performance thermoplastic composites, specifically PEEK and PEKK. The study aims to produce lightweight composites suitable for industrial applications by investigating the impact of various process parameters on the quality of composite parts. The results for hand tape layup followed by thermoforming achieve excellent consolidation under 40 𝑏𝑎𝑟 and 390 ℃ of 16 plies in a (0°/90/0°/90°/0°/90°/0°/90°)𝑆 sequence. Tensile testing of manually prepared samples using ‘Araldite 2014-2’ and TII sandblast exhibited robust mechanical properties and yielded a tensile modulus of approximately 82.07 𝐺𝑃𝑎, while AFP without post-consolidation showed decreased stiffness by approximately 24.8%, with a modulus of 61.7𝐺𝑃𝑎. The failure strain was reduced by approximately 26.2%, highlighting decreased ductility. The SBS results showed a significant decrease in resistance to interlaminar shear forces, with a decrease of approximately 93.1% compared to manual layup. In contrast, AFP with thermoforming demonstrated improvements over AFP without post-consolidation. The tensile modulus increased by approximately 57.7 %, reaching 97.3 𝐺𝑃𝑎, while tensile strength saw a remarkable enhancement of nearly 97. 2 %, reaching 928.2 M𝑃𝑎. The SBS showed a notable enhancement of approximately 1232.0 % compared to AFP without thermoforming. The results prove the significant impact of thermoforming on enhancing the mechanical properties of AFP-produced thermoplastic composites. The study concludes that while the manual manufacturing process demonstrated consistency, AFP samples exhibited structural instability and inconsistencies, necessitating post-processing like thermoforming for reliability.

Date of Award	21 May 2024
Original language	American English
Supervisor	Wael Zaki (Supervisor)