Marine Applications of Advanced Fibre-reinforced Composites

Jasper Graham-Jones, John Summerscales

• Publisher: Woodhead Publishing
• Year: 2015
• ISBN:
  9780081002001
• Topic: Technology & Engineering
• Subtopic: Military Science & Technology
• Index: Technology & Engineering

The marine environment presents significant challenges for materials due to the potential for corrosion by salt water, extreme pressures when deeply submerged and high stresses arising from variable weather. Well-designed fibre-reinforced composites can perform effectively in the marine environment and are lightweight alternatives to metal components and more durable than wood. Marine Applications of Advanced Fibre-Reinforced Composites examines the technology, application and environmental considerations in choosing a fibre-reinforced composite system for use in marine structures.

This book is divided into two parts. The chapters in Part One explore the manufacture, mechanical behavior and structural performance of marine composites, and also look at the testing of these composites and end of life environmental considerations. The chapters in Part Two then investigate the applications of marine composites, specifically for renewable energy devices, offshore oil and gas applications, rigging and sails. Underwater repair of marine composites is also reviewed.

• Comprehensively examines all aspects of fibre-reinforced marine composites, including the latest advances in design, manufacturing methods and performance
• Assesses the environmental impacts of using fibre-reinforced composites in marine environments, including end of life considerations
• Reviews advanced fibre-reinforced composites for renewable energy devices, rigging, sail textiles, sail shape optimisation and offshore oil and gas applications

1

Introduction

J. Graham-Jones; J. Summerscales University of Plymouth, Plymouth, UK

Abstract

The marine environment is challenging for traditional engineering materials due to corrosion of metals or for natural materials due to other degradation routes. Since the middle of the twentieth century, the use of fibre-reinforced polymer matrix composites in the seas and oceans has grown in both component/structure size and numbers. Composites have repeatedly demonstrated good performance, such that many technologies and developments would not exist without their use. This chapter introduces the purpose of the book, then provides signposts to the topics covered within the book or to alternative sources for defects, durability and developing technologies, including anti-fouling, biomimetics and smart materials.

Keywords

Fibre-reinforced composites

Damage

Durability

Anti-fouling

Biomimetics

Smart materials.

1.1 Introduction

The marine environment stretches from tidal estuaries, through the coastal and littoral (defined as on or near a shore) zones, out into the seas and onwards to the depths of the ocean. Systems operating in this environment are subject to stresses arising from wind, waves and tides and may be anywhere between wholly submerged (and at great depth) in salt water or partially exposed in the splash zone.

The composition of seawater changes with location due to eroded materials, and agricultural run-off, being carried to the sea from inland watercourses. As well as being the natural environment for marine animals and plants, a typical composition for 1 kg of seawater (Kester et al., 1967) would include 19.4 g Cl⁻, 10.8 g Na⁺, 2.7 g SO₄^{2 −}, 1.3 g Mg^{2 +}, 0.4 g Ca^{2 +}, 0.4 g K⁺, 0.1 g HCO₃⁻, 0.1 g Br⁻ and other trace chemicals at lower levels. This salt water environment is corrosive to most engineering metals and, in combination with marine animals such as the naval shipworm (Teredo navalis), and gribble (Limnoriidae) causes rapid deterioration of wood.

The incorporation of synthetic (e.g. aramid, carbon, glass) fibres into a synthetic polymeric matrix produces a composite material. With well-selected constituents, these fibre-reinforced plastics (FRP) can provide excellent performance in the marine environment while being resistant to the biological and chemical attack which other materials suffer.

The use of composites in marine structures has been the subject of a number of earlier books (Smith, 1990; Eric Greene Associates, 1999; Shenoi and Wellicome, 2008a,b) although the best of these, by the late Charles Smith, is now twenty-five years old. It is thus timely to review the latest advances in this area. For readers new to the area of composites, we recommend the following starter texts (Cystic Composites Handbook, 2005; Guide_to_Composites, 2013; Hull and Clyne, 1996; Åström, 1997).

For the purpose of this book, we define advanced composites as those FRP systems which use continuous fibre reinforcements. Further, we define four categories of composite:

• monolithic composite material: all layers aligned parallel;

• laminated composite structure: orientation changes between layers;

• hybrid structures: more than one type of fibre (e.g. carbon/glass); and

• sandwich structures: composite skins and lightweight core

1.2 What is in the book

This book comprises two distinct sections. In Part One, the topics progress from manufacture of composites (Chapter 2) and sandwich structures (Chapter 3), through the effects of mechanical (Chapter 4) and environmental (Chapter 5) stresses, via suitability for deep submergence (Chapter 6) to non-destructive testing and structural health monitoring (Chapter 7) before closing with consideration of the end-of-life implications of choosing composites (Chapter 8).

Part Two addresses applications of advanced fibre-reinforced composites. It opens with marine renewable energy (MRE: wave, tidal, etc.) devices (Chapter 9), offshore oil and gas composites (Chapter 10) and underwater repair with composites (Chapter 11). This section closes with rigging (Chapter 12), sail shape optimisation (Chapter 13) and advanced sail materials, including Thin Ply Technology (TPT) (Chapter 14).

1.3 What is not in the book

In respect of material not directly covered by this volume, the following resources will guide the reader to alternative sources for:

1.3.1 Defects

A distinction can be made between defects, as faults incorporated during manufacture, and damage (Section 1.3.2). The principal defects found in composites include:

• errors in manufacturing, including fibre misalignment or waviness, incorrect laminate stacking sequence and unintended inclusions;

• voids, being discrete spherical or elongated bubbles;

• porosity, being inter-connected voids;

• under- or over-cure;

• issues arising from damp raw materials;

• inadequate fibre-matrix adhesion; and

• delamination, due to failure to achieve the initial bond between layers.

For more information on these issues see Judd and Wright (1978), Adams and Cawley (1988), Heslehurst and Scott (1990), Cantwell and Morton (1992), Ghiorse (1993), Summerscales (1994), Senthil et al. (2013) and Baley et al. (2015).

1.3.2 Mechanical damage

During manufacture, and especially in service, mechanical damage (Garg, 1988; Hull and Bing Shi, 1993; Fan et al., 2010; Belingardi et al., 2013) may be inflicted through a variety of mechanisms, primarily due to over-stressing the component. This may occur in a single monotonic event (quasi-static), by extended exposure to high static loads (creep), by repeated loading cycles (fatigue) or by impulsive loading (impact) (Porfiri and Gupta, 2010; Agrawal et al., 2014).

Life prediction modelling for advanced marine composite structures could ensure structural reliability and safety. Backman (2005, 2008) considered how safety methods can be made available to the engineering community for reliability analysis without requiring huge statistical databases. Whilst his book primarily considers the probability of safe flight, it is perhaps essential reading for offshore and marine sector structural design, as much of the analysis is undertaken at the level of orders of magnitude rather than in fine detail. The consideration of probability of detection (POD) a...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• List of contributors
• Acknowledgements
• Woodhead Publishing Series in Composites Science and Engineering
• 1: Introduction
• Part One: Manufacture, Performance, Testing and Disposal
• Part Two: Applications of Advanced Fibre-Reinforced Composites in Marine Structures
• Index