Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557959
Title: Investigating 3D woven composite architecture
Author: Mahadik, Yusuf
Awarding Body: University of Bristol
Current Institution: University of Bristol
Date of Award: 2011
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Abstract:
Composite parts reinforced with unidirectional or 2D woven reinforcements have been widely used for many years in numerous industries from aerospace to automotive parts. Although their use is widespread, laminated reinforcements have some significant weaknesses that limit their usefulness, including poor interlaminar strength and high cost driven by the need for lengthy hand lay-up to create complex parts. Considerable effort has been put into developing three-dimensional composite reinforcement in order to alleviate these problems. This thesis focuses on materials produced via the weaving method. "3D weaving" can produce fabrics with interlacing yams that provide genuine through thickness reinforcement. The weaving process can also produce multi-layer fabrics, reducing the amount of lay-up required to produce thick parts. A review of current literature showed that 3D woven composites have good interlaminar properties but can have poor in-plane mechanical properties, the main cause being architectural distortions such as local yam crimp and resin rich regions. It was evident that there has been relatively little study into the detail of 3D woven architecture and how it is affected by forming forces and in turn how this affects mechanical properties. In addition, [mite element modelling of 3D woven fabrics has been limited by idealised mesh generation, hampering predictive fabric analysis. The work presented here addresses the issue by developing a fundamental understanding of 3D woven composite architecture via a detailed characterisation of yam crimp and resin channels for a selection of angle-interlock weaves. The effect of compaction on these architectural features was also investigated and coupled with an innovative use of kinematic modelling that could help predict the final internal state of a compacted 3D woven fabric. Finally, compression testing of specimens reinforced using 3D woven fabrics at a range of compaction levels was used to ascertain the influence of fabric architecture on mechanical properties.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.557959  DOI: Not available
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