E-Thesis 195 views
Experimental and Numerical Investigations on a Flexible Membrane Wave Energy Converter / IEUAN COLLINS
Swansea University Author: IEUAN COLLINS
DOI (Published version): 10.23889/SUthesis.64081
Abstract
The aim of this thesis was to provide a basis for successful development of novel flexible membrane wave energy converters (FlexWECs) through the development of experimental test procedures and computational tools. The initial goals were to perform the first large-scale comprehensive literature revi...
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Swansea, Wales, UK
2023
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Hossain, Mokarram. and Masters, Ian. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa64081 |
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| Abstract: |
The aim of this thesis was to provide a basis for successful development of novel flexible membrane wave energy converters (FlexWECs) through the development of experimental test procedures and computational tools. The initial goals were to perform the first large-scale comprehensive literature review on possible design configurations, material composites appropriate for the structure and then give an overview of the current modelling options available. From the literature study, the biggest knowledge gap identified related to elastomeric materials in experimental testing and computational modelling for FlexWECs; prompting an investigation in these areas. The first part of PhD is spent testing elastomeric materials for time-dependent behaviour, marine environment deterioration, and fatigue loading. Experiments found moderate degrees of viscoelasticity in pure rubber, but this rises with particle reinforcement. Seawater ageing may considerably modify a material's stiffness, although the outcomes arise over extremely long time scales and fatigue loading mechanisms are predicted to dominate the deterioration process. Ageing had little influence on the fatigue life of the material analysed. As part of this PhD, a bespoke experimental test facility for characterising elastomeric materials which takes into account seawater and biaxial loading conditions has been developed for Swansea University. The second portion presents a viscoelasticity and damage modelling methodology applied to FlexWEC architectures. The rst case study examines the long-term effects of material relaxation and hysteresis on energy harvesting. Long-term creep is important for FlexWECs because material characteristics can change the pressurisation properties causing catastrophic failures. It was found that hysteresis has a small influence on the dynamic behaviour of a FlexWEC. The second case study focused on membrane degradation and inhomogeneous softening. Non-local damage effects caused a different failure mode and lower maximum pressure than a global damage model. |
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| Item Description: |
A selection of third party content is redacted or is partially redacted from this thesis due to copyright restrictions. |
| Keywords: |
Mechanical Engineering, Wave Energy, Solid Mechanics, Flexible Membranes, Ocean Engineering, Experimental Characterisation, Viscoelasticity, Damage Mechanics |
| College: |
Faculty of Science and Engineering |