Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595602
Title: The use of optical techniques to assess the damage tolerance of composite materials
Author: Battams, Gary
ISNI:       0000 0004 5349 2854
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 2014
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Abstract:
Experimental methodologies based on full-field optical techniques for the study of damage in fibre reinforced polymer (FRP) materials, during intermediate strain rate loading and subsequent fatigue loading are established. The methodologies are based on thesynchronous use of digital image correlation (DIC) and infra-red (IR) thermography, allowing the collection of full-field kinematic and thermal surface data maps to provide a deeper insight into the damage mechanisms and a new capability for identifying damage in FRP materials and structures. The study of damage initiation in FRP materials during intermediate strain rate loading requires the application of high speed cameras and the development of a novel loading rig capable of imparting a damaging load that does not fail the material. The rig design is fully validated. The application of DIC on images obtained using high speed cameras is evaluated. New approaches to identify the effect of sensor fill-factor on the accuracy of high spatial resolution DIC strain measurements are devised. Data captured from crossply carbon-epoxy and glass-epoxy specimens demonstrate the capability of combining DIC and IR-thermography in identifying damage during an intermediate strain rate loading event. A novel semi-automated methodology for the accurate triggering of high resolution white-light and IR images during a fatigue test is described, which allows the synchronous capture of data that enables DIC and thermoelastic stress analysis (TSA) to be applied without the pausing of a cyclic load. The combined methodology is applied to crossply glass-epoxy and carbon-epoxy specimens, identifying various damage types including; transverse cracking, delaminations and longitudinal splitting, verified through the use of X-ray computed tomography (CT). Finally, future improvements are recommended with an aim of future users applying the optical methodologies to a greater range of loading scenarios and to the study of a greater range of material types and laminate configurations, so informing on the future design of damage tolerant FRP structures.
Supervisor: Barton, Janice Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.595602  DOI: Not available
Keywords: QC Physics ; TJ Mechanical engineering and machinery ; TK Electrical engineering. Electronics Nuclear engineering
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