Study on design allowables for fibre-steered laminated composites in aircraft structures

This PhD studentship is a collaboration between the University of Bristol and Embraer SA based in Brazil who is the world's third largest producer of civil aircraft. The research will explore the feasibility of applying novel fibre-steering design to composite aircraft structures, focusing mainly on the challenges arising in evaluating the design allowables for the laminates including curved fibres. Although the current state-of-the-art, automated fibre placement (AFP) technology, enables the fibre steering in production of composite aerospace structures, the process-induced defects is the most critical problem in realising such a design as the defect generation mechanism is complex and material-dependent. Furthermore, there is no standard suitable for determining the design allowables for the fibre-steered laminates that can take into account the effect of the curved fibres in the structure and the defects. The project will start by reviewing the current industrial practice for design allowables of straight fibre laminates and identifying its limitation for fibre-steered laminates. The research will consider modifying or developing new test methods and/or specimen designs to address the unique aspects of the laminates including curved fibres and manufacturing defects, and their impact on the structural integrity will be studied through an extensive coupon testing programme and rigorous evaluation of the test results. The test specimens will be manufactured to reflect the manufacturing characteristics of the AFP and a novel fibre steering technology developed at the University of Bristol, Continuous Tow Shearing. The studentship will be jointly supervised by the academic and industrial supervisors, and a unique opportunity for a short secondment at Embraer will be provided