Environmental Effect On Composite Material.

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ENVIRONMENTAL EFFECT ON COMPOSITE MATERIAL

MOHD SYAHIR ASYRAF BIN MOHAMMED TAHIR

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ENVIRONMENTAL EFFECT ON COMPOSITE MATERIAL

MOHD SYAHIR ASYRAF BIN MOHAMMED TAHIR

Report submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Mechanical Engineering (Structure and Material)

Faculty of Mechanical Engineering University of Technical Malaysia Melaka

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We hereby declare that we have checked this project report and in our opinion this project

is satisfactory in terms of scope and quality for the award of the degree of Bachelor of Mechanical Engineering (Structure and Material)

Signature :

Name of Supervisor : MR AHMAD RIVAI

Position : Lecturer

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iii

“I hereby declare this project report is my own work base on my scope except the quotations and summaries which have been duly acknowledged”

Signature :

Name : MOHD SYAHIR ASYRAF BIN MOHAMMED TAHIR

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WLEDGEMENTS

First of all, I am very grateful to Allah S.W.T, for giving me opportunity to finish my Final Year Project. I want to express my greatest attitude and appreciation to the following person and organizations that have directly or indirectly given generous contributions towards the success of this project.

I would like to thanks my project supervisor, En. Ahmad bin Rivai for his consistent guidance and advice throughout the project preparation and sharing his knowledge and experiences in finishing this project. This project would not be able to be completed in time without his constant encouragement and guidance.

Then, my special gratitude to my family for the unconditional faith during bad times always ignited a new spark of motivation. I also would like to thank all my friends that helps and gave valuable advices and tips when I encountered problems during the preparation of this project. Lastly, I also like to express my gratitude and thanks to Universiti Teknikal Malaysia Melaka (UTeM) for having such a complete and resourceful library.

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ABSTRACT

One of the obstacles hindering the acceptance of composite material in engineering applications is the susceptibility of the composite to degradation initiated by moisture, temperature, and corrosive chemical environments. This thesis was conducted to investigate the environmental effect on the composites material. The primary objective of this study was to determine the flexural properties and the mechanical properties of Glass Fiber Reinforced Plastic (GFRP) after exposed to water and elevated temperatures for extended periods of time. The works done includes a thorough literature review, experiments and determine the flexural properties of the GFRP composites under different environmental conditions. Changes in the modulus of elasticity and flexural properties were evaluated through 3 point bending test machine. The experiment used the Universal Testing Machine model Instron 5585.

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ABSTRAK

Satu daripada proses yang menghalang penerimaan bahan komposit didalam aplikasi kejuruteraan adalah kesan buruk komposit terhadap pengaruh kelembapan, suhu dan persekitaran bahan kimia. Tesis ini dihasilkan untuk menyiasat kesan alam sekitar terhadap bahan komposit. Objektif utama dalam tesis ini adalah untuk menyatakan keadaan sifat elastik bahan dan sifat-sifat mekanik bahan Glass Fiber Reinforced Plastic (GFRP) selepas bahan tersebut terdedah di dalam air dan pada suhu berbeza dalam masa yang tertentu. Projek ini berjalan melibatkan kajian ilmiah, eksperimen dan menyatakan sifat-sifat keadaan elastik bahan Glass Fiber Reinforced Plastic (GFRP) dibawah keadaan sekeliling yang berbeza. Perubahan nilai modulus elastik dan sifat-sifat keadaan elastik dicatatkan melalui mesin uji kelenturan tiga titik. Eksperimen ini mengunakan mesin Universal Testing Machine model Instron 5585.

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viii

TABLE OF CONTENT

CHAPTER CONTENT PAGE

DECLARATION ii

DEDICATION iv

ACKNOWLEDGEMENT v

ABSTRACT vi

CONTENTS vii

LIST OF TABLE x

LIST OF FIGURE xi

LIST OF SYMBOL xiii

LIST OF APPENDICES xiv

CHAPTER 1 INTRODUCTION

1.1 Background of Project 1

1.2 Problem Statement 2

1.3 Objective 2

1.4 Scopes 3

CHAPTER 2 LITERATURE REVIEW

2.1 Introduction 4

2.2 What makes a material a composite 4 2.3 History of composite materials 5

2.4 Advantages of composites 5

2.5 Glass Fiber Reinforced Plastic (GFRP) 7

2.6 Style of woven fabrics 7

2.7 Chopped Strand Mat (CSM) 8

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2.9 Properties of GFRP 10

2.10 Environmental Factors Affecting GFRP 12

2.11 Type of tests 16

2.12 Bending test 16

2.13 Flexure bending test 17

2.14 Why perform a flexure test? 18

2.15 Types of flexure test 19

2.16 Flexure strength 19

2.17 Flexure strength testing of plastic 22

CHAPTER 3 METHODOLOGY

3.1 Introduction to Methodology 23

3.2 Flow Chart PSM I 24

3.3 Flow Chart PSM II 25

3.4 GFRP reinforcing bar specimen 26

3.5 Recourses used 26

3.6 Environmental selection 27

3.7 Running the experiment 29

CHAPTER 4 RESULTS

4.1 Introduction 33

4.2 Interpretations from the Data 33

4.3 Overview of the Data 35

4.4 Calculation 37

4.5 Analysis Graph 39

CHAPTER 5 DISSCUSSION 48

CHAPTER 6 CONCLUSION AND RECOMMENDATIONS 51

REFERENCES 53

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LIST OF TABLES

No Title Page

1 Mechanical properties [13,14] 7

2 Fibers and Metal 11

3 Material Properties 11

4 Flexural test result exposed in normal room temperature 35

5 Flexural test result exposed in mineral water 35

6 Flexural test result exposed in seawater 35

7 Flexural test result exposed in fridge 36

8 Flexural test result exposed in high temperature 36

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LIST OF FIGURES

No Title Page

1 Weave styles 8

2 Chopped strand mat (CSM) 8

3 Rough estimate of alkali penetration in GFRP rods [After Katsuki and Uomoto (1995)]

4 Graph of flexure stress versus flexure strain 18

5 Flexural test with three-point bending 19

6 Specimen is placed on two supports and a load is applied at the center

22 7 Typical Curves of Flexural Stress versus Flexural Strain 30

8 Direction of Loading Specimen 31

9 Specimen setup on the test machine 32

10 Graph Flexure Stress versus Flexure Strain from the experiment for specimen 1 when exposed in normal room.

33 11 Typical Curves of Flexural Stress (§f) Versus Flexural Strain (έf) 34 12 Graph the average of maximum load of each exposed specimen 39 13 Graph the average of maximum stress of each exposed specimen 40 14 Graph the average of flex modulus of each exposed specimen 41 15 Graph the average of flexure stress of each exposed specimen at

maximum flexure load

42 16 Graph the average of flexure strain of each exposed specimen at

maximum flexure stress

43 17 Graph Flexure Stress versus Flexure Strain (Normal Room) 44 18 Graph Flexure Stress versus Flexure Strain (Mineral Water) 44 19 Graph Flexure Stress versus Flexure Strain (Seawater) 45 20 Graph Flexure Stress versus Flexure Strain (In Fridge) 45

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xii

21 Graph Flexure Stress versus Flexure Strain (High Temperature) 46 22 Graph Flexure Stress versus Flexure Strain (Average) 47

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xiii

LIST OF SYMBOLS

P _{Applied Load}

L _{Span Length}

b _Width

t _Thickness

E _{Elastic Modulus}

G _{Shear Modulus}

ks _{Shear Coefficient}

GFRP Glass Fiber Reinforced Plastic FRP Fiber Reinforced Polymers CFRP Carbon Fiber Reinforced Polymers AFRP Aramid Fiber Reinforced Polymers

CSM Chopped Strand Mat

EPMA Electron Prove Microscope Analyzer Stress

R _{Rate of Crosshead Motion}

Z _{Rate of Straining}

D _{Midspan Deflection}

R _{Strain, mm/mm (in./in.),}

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xiv

LIST OF APPENDICES

No Title Page

A The Universal Testing Machine model Instron 5585 54 B

C D

Specimen setup on the test machine

The GFRP specimen in normal room temperature, mineral and seawater condition

Data result from flexural test

55 56 56

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.1 Background of Project

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2 1.2 Problem Statement

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3 1.4 Scopes

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4 CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

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2.2 What Makes A Material A Composite?

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2.4 Advantages of Composites

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producing something like a surfboard or a boat hull.

The downside of composites is usually the cost. Although manufacturing processes are often more efficient when composites are used, the raw materials are expensive. Composites will never totally replace traditional materials like steel, but in many cases they are just what we need. And no doubt new uses will be found as the technology evolves.

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7 2.5 Glass Fiber Reinforced Plastic (GFRP)

Glass Fiber Reinforced Plastic is a substance composed of a plastic matrix that is embedded with glass fibers to provide strength and reinforcement. Fiber reinforced polymer is used to build architectural elements, car parts, bridges, and consumer products. Fiber Reinforced Polymer reinforcing bars are typically made up of one of three types of fibers –glass, carbon and aramid. Glass fibers are the most popular of all the fibers used for reinforcement due to their relatively lower costs. Table 1 presents some mechanical properties of the reinforcing bars made up of different fibers as compared to steel.

Table 1 –Mechanical properties [13, 14]

Tensile Strength Modulus of Elasticity Density

MPa GPa g/cc

GFRP 483-1035 35-45 2.58

CFRP * 600-2900 120-300 1.8

AFRP ** 1000-1400 60-87 1.45

Steel 483-690 200 7.8

* CFRP is Carbon Fiber Reinforced Polymers. ** AFRP is Aramid Fiber Reinforced Polymers.

2.6 Style of Woven Fabrics

Fabrics consist of at least two threads, which are woven together: the warp and the weft. The weave style can be varied according to crimp and drapeability. Low crimp gives better mechanical performance because straighter fibres carry greater loads: a drapeable fabric is easier to lay-up over complex forms. There are four main weave styles (see Figure 1).

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Figure 1: Weave styles

2.7 Chopped Strand Mat (CSM)

Chopped strand mat is made from E-glass fiber strands chopped to different lengths and bonded in one of two ways either powder or emulsion. It is the most common form of reinforcement. Chopped strand mat is used primarily for hand lay-up processes, filament winding and press molding of FRP products including bathroom accessories, pipes, automobiles and other building applications.

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Chopped strand mat (CSM) is a non-woven material which as its name implies, consists of randomly orientated chopped strands of glass which are held together. Despite the fact that PVA imparts superior draping handling and wetting out characteristics users in a marine environment should be wary of its use as it is affected by moisture and can lead to osmosis like blisters. Today, chopped strand mat is rarely used in high performance composite components as it is impossible to produce a laminate with high fiber content and by definition, a high strength-to-weight ratio.

2.8 GFRP Fabrication: How it’s made

Although all types of Glass Fiber Reinforced Plastic are composed of a plastic matrix and glass fibers, there are actually several fiber reinforced polymer manufacturing methods that are commonly used.

The first method of manufacturing Glass Fiber Reinforced Plastic is what is known as the hand lay-up method. Although very precise, this method is also quite labor intensive. In the hand lay-up method, a resin that has been combined with a catalyst is placed inside of a mold. Fiberglass is then packed into the mold with steel rollers. This process may be repeated one or more times. The resin will usually start to cure quite quickly, depending on the exact amount of catalyst used, so the task must be completed relatively fast when this method of GFRP fabrication is used.

Another common method of GFRP fabrication is the spray lay-up process. It is similar to the former method in many respects. The main difference is how the resin and glass fibers are placed into the mold. Instead of being placed into molds by hand, these substances are sprayed in. Not surprisingly, this method of fabricating fiber reinforced polymer is faster than the previous.

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CHAPTER 2 LITERATURE REVIEW

2.1 Introduction

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