Hydroelastic waves and their interaction with fixed structures

• Main Author: Brocklehurst, Paul
• Format: Thesis
• Language: English
• Published: 2012
• Subjects: Ice Sheet
• Online Access: https://ueaeprints.uea.ac.uk/id/eprint/47911/; https://ueaeprints.uea.ac.uk/id/eprint/47911/1/2012BrocklehurstPPhD.pdf

A selection of problems are presented which study the interaction of hydroelastic waves with fixed structures. A thin floating elastic plate model is considered which primarily represents a continuous floating ice sheet, but may also be applied to very large floating platforms. The incident hydroelastic waves are assumed to either propagate from long–distance towards the structures or be generated by a moving load. All aspects of the subsequent interaction are studied in detail. The elastic plate is clamped to the fixed vertical structures to model an ice sheet frozen to the structure boundary. Both linear and nonlinear formulations are admitted for a selection of two– and three–dimensional problems. For the linear problems, selection of appropriate integral transforms leads to explicit analytical solutions in terms of integral quadratures. For the nonlinear case, the numerical solution is found by application of Green’s second identity combined with a boundary element method. The resulting deflection fields are analysed as well as the strain in the ice sheet due to curvature from the hydroelastic waves. Particular attention is paid to the strain at the ice–structure boundary. The integral transforms also lead to concise expressions for the horizontal and vertical wave forces impacting on the structure. It is shown that these forces may reach a substantial magnitude and must be taken into account for the design of structures in ice–covered water. Several assumptions are utilised which allow the problems to be mathematically treatable while retaining accuracy. Realistic effects such as viscoelasticity and fluid stratification are studied. The solutions are investigated in detail under the variation of physical parameters of the fluid, the ice sheet and the incident/load–generated waves, based on realistic values from cold climate regions.