The use of fibre-reinforced polymer matrix composite materials is growing at a faster rate
than GDP in many countries. An improved understanding of their processing and mechanical
behaviour would extend the potential applications of these materials. For unidirectional
composites, it is predicted that localised absence of fibres is related to longitudinal
compression failure. The use of woven reinforcements permits more effective manufacture
than for unidirectional fibres. It has been demonstrated experimentally that compression
strengths of woven composites are reduced when fibres are clustered. Summerscales
predicted that clustering of fibres would increase the permeability of the reinforcement and
hence expedite the processing of these materials. Commercial fabrics are available which
employ this concept using flow-enhancing bound tows. The net effect of clustering fibres is
to enhance processability whilst reducing the mechanical properties. The effects reported
above were qualitative correlations. Gross differences in the appearance of laminate sections
are apparent for different weave styles. For the quantification of subtle changes in fabric
architecture, the use of automated image analysis is essential. Griffm used Voronoi
tessellation to measure the microstructures of composites made using flow-enhancing tows.
The data was presented as histograms with no single parameter to quantify microstructure.
This thesis describes the use of automated image analysis for the measurement of the
microstructures of woven fibre-reinforced composites, and pioneers the use of fractal
dimensions as a single parameter for their quantification. It further considers the process-property-
structure relationships for commercial and experimental fabric reinforcements in an
attempt to resolve the processing versus properties dilemma. A new flow-enhancement
concept has been developed which has a reduced impact on laminate mechanical properties.
Date of Award | 2001 |
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Original language | English |
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Awarding Institution | |
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Supervisor | John Summerscales (Other Supervisor) & Felicity Guild (Other Supervisor) |
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PROCESS-PROPERTY-FABRIC ARCHITECTURE RELATIONSHIPS IN FIBRE-REINFORCED COMPOSITES
PEARCE, N. R. L. (Author). 2001
Student thesis: PhD