The University of Southampton
University of Southampton Institutional Repository

Genetic algorithm based optimisation of FRP composite plates in ship structures

Genetic algorithm based optimisation of FRP composite plates in ship structures
Genetic algorithm based optimisation of FRP composite plates in ship structures
Composite materials (herein means Fibre Reinforced Plastic, FRP) are increasingly usedin the construction of marine vehicles because of their outstanding strength, stiffness and light weight properties. However, the use of FRP comes with difficulties in the design process as a result of the large number of design variables involved: composite material design, topologies and laminate schemes. All variables are related to each other leading to a high dimensional and flexible design space. It is hard to use traditional design methods in order to gain solutions for an initial design stage in a short time. Hence, this thesis deals with the presentation of a structural synthesis (optimisation framework) for plate components of composite ship structures. The framework broadly consists of an optimisation technique and structural analytical methods.
To make the framework compatible with the nature of composite ship structural design problems, the Genetic Algorithm (GA) is selected as the optimisation tool because of its robustness, its ability in dealing with both continuous and discrete variables and its excellent searching for a global optimum. The typical plate types in a ship structure are the stiffened and unstiffened plates. For a stiffened plate, the combination of the grillage analysis of energy method based on Navier solution and an equivalent elastic properties approach are introduced. Using this, it is possible to produce layer by layer optimisation results for the base plate, web and crown of the stiffened plate. Unfortunately, solutions of the adopted grillage analysis do not cover the mechanical behaviour of the plate between stiffeners so the Higher-Order Shear Deformation Theory (HSDT) must be employed.
This method provides accurate solutions for thin to moderately thick plates with a compromised computational time. Then stiffness, strength and stability can be considered in the design problem. In addition, to achieve the program of the structural synthesis, various computational modules are implemented according to the evaluation of composite micromechanics properties, maximum stress failure criteria and structural weight function. Then the main modules are validated with available resources. The usefulness of the program has been proved by comparing it with the optimal solutions from finite element software. Finally, many application examples of secondary and tertiary composite ship structures are presented. The optimal results prove the success of the optimisation framework. This could be evidence for further improvement to obtain a valuable structural optimisation tool.
Maneepan, Komsan
d8b4475d-0d09-44c3-ad43-834564bea571
Maneepan, Komsan
d8b4475d-0d09-44c3-ad43-834564bea571

Maneepan, Komsan (2007) Genetic algorithm based optimisation of FRP composite plates in ship structures. University of Southampton, School of Engineering Sciences, Doctoral Thesis, 157pp.

Record type: Thesis (Doctoral)

Abstract

Composite materials (herein means Fibre Reinforced Plastic, FRP) are increasingly usedin the construction of marine vehicles because of their outstanding strength, stiffness and light weight properties. However, the use of FRP comes with difficulties in the design process as a result of the large number of design variables involved: composite material design, topologies and laminate schemes. All variables are related to each other leading to a high dimensional and flexible design space. It is hard to use traditional design methods in order to gain solutions for an initial design stage in a short time. Hence, this thesis deals with the presentation of a structural synthesis (optimisation framework) for plate components of composite ship structures. The framework broadly consists of an optimisation technique and structural analytical methods.
To make the framework compatible with the nature of composite ship structural design problems, the Genetic Algorithm (GA) is selected as the optimisation tool because of its robustness, its ability in dealing with both continuous and discrete variables and its excellent searching for a global optimum. The typical plate types in a ship structure are the stiffened and unstiffened plates. For a stiffened plate, the combination of the grillage analysis of energy method based on Navier solution and an equivalent elastic properties approach are introduced. Using this, it is possible to produce layer by layer optimisation results for the base plate, web and crown of the stiffened plate. Unfortunately, solutions of the adopted grillage analysis do not cover the mechanical behaviour of the plate between stiffeners so the Higher-Order Shear Deformation Theory (HSDT) must be employed.
This method provides accurate solutions for thin to moderately thick plates with a compromised computational time. Then stiffness, strength and stability can be considered in the design problem. In addition, to achieve the program of the structural synthesis, various computational modules are implemented according to the evaluation of composite micromechanics properties, maximum stress failure criteria and structural weight function. Then the main modules are validated with available resources. The usefulness of the program has been proved by comparing it with the optimal solutions from finite element software. Finally, many application examples of secondary and tertiary composite ship structures are presented. The optimal results prove the success of the optimisation framework. This could be evidence for further improvement to obtain a valuable structural optimisation tool.

Text
maneepan2007_thesis.pdf - Other
Download (1MB)

More information

Published date: 21 August 2007
Organisations: University of Southampton, Fluid Structure Interactions Group

Identifiers

Local EPrints ID: 52012
URI: http://eprints.soton.ac.uk/id/eprint/52012
PURE UUID: b95973ef-721c-405b-8cfc-7b614ac00683

Catalogue record

Date deposited: 02 Jun 2008
Last modified: 15 Mar 2024 10:19

Export record

Contributors

Author: Komsan Maneepan

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×