SPRINGBACK DEFORMATION MEASUREMENT OF COMPOSITE USING 3D SCANNER AFTER CURING PROCESS
DEVAN A/L SANMUGAM
UNIVERSITI TEKNIKAL MALAYSIA MELAKA
S.DE V A N BA CHE LO
R OF MECH
A N ICAL EN G IN EE RIN G (STRUCTU
RE & MA
SUPERVISOR DECLARATION
“I hereby declare that I have read this thesis and in my opinion this thesis is sufficient in terms of scope and quality for the award of degree in
Bachelor of Mechanical Engineering (Structure and Material) (Hons.)”
Signature :
SPRINGBACK DEFORMATION MEASUREMENT OF COMPOSITE USING 3D SCANNER AFTER CURING PROCESS
DEVAN A/L SANMUGAM
This thesis is submitted in partial fulfillment for the award of
Bachelor of Mechanical Engineering (Structure and Material) (Hons.)
Faculty of Mechanical Engineering Universiti Teknikal Malaysia Melaka
DECLARATION
“I hereby declare that the work in this thesis is my own except for summaries and quotations which have been duly acknowledged.”
Signature :
iii
1 DEDICATION
ACKNOWLEDGEMENT
v
ABSTRACT
ABSTRAK
vii
2 TABLE OF CONTENT
CHAPTER TOPIC PAGES
DECLARATION ... ii
DEDICATION ... iii
ACKNOWLEDGEMENT... iv
ABSTRACT ... v
ABSTRAK ... vi
TABLE OF CONTENT... vii
LIST OF TABLES ... x
LIST OF FIGURES ... xii
LIST OF ABBREVIATIONS ... xvi
LIST OF APPENDICES ... xvii
CHAPTER 1 INTRODUCTION ... 1
1.1 Background ... 1
1.2 Problem Statement ... 2
1.3 Objective ... 3
1.4 Scope ... 3
CHAPTER 2 LITERATURE REVIEW ... 4
2.1 Introduction ... 4
2.2 Phenomenon Of Springback Deformation ... 4
2.2.1 Causes Of Springback Deformation ... 5
CHAPTER TOPIC PAGES
2.3 Methods Of Measuring Springback Deformation .. 16
2.3.1 Coordinate Measuring Machine (CMM) 16 2.3.2 Laser Tracker ... 19
2.3.3 3D Scanner ... 21
2.4 Prediction Of Springback Deformation... 23
CHAPTER 3 METHODOLOGY ... 27
3.1 Introduction ... 27
3.2 Flow Chart Of The Project ... 27
3.3 Specimen Specifications ... 30
3.3.1 Specimen Manufacturing Process... 31
3.3.2 Specimen Parameters ... 34
3.4 Scanning Process ... 37
3.4.1 Scanning Devices And Materials Used . 37 3.4.2 Scanning Procedures ... 38
3.5 Measuring Process... 44
3.5.1 Springback Measurement For Flat Specimens ... 44
3.5.2 Springback Measurement For L-Shaped Specimens ... 46
CHAPTER 4 RESULTS AND ANALYSIS ... 50
4.1 Introduction ... 50
4.2 Springback Deformation Data For Flat Specimens 50 4.3 Springback Deformation Data For L-Shaped Specimens... 60
CHAPTER 5 DISCUSSION ... 67
5.1 Introduction ... 67
5.2 Effect Of Thickness ... 67
5.3 Effect Of Length... 69
ix
CHAPTER TOPIC PAGES
CHAPTER 6 CONCLUSION AND RECOMMENDATION ... 73
6.1 Conclusion ... 73
6.2 Recommendation ... 74
REFERENCES... 75
3 LIST OF TABLES
NO TABLE PAGES
2.1 Main Components Of CMM And Respective Functions 17 2.2 Main Components Of Laser Tracker And Respective Functions 20 2.3 Main Components Of 3D Scanner And Respective Functions 22 3.1 Physical Properties Of IMA/M21E Carbon Fiber Prepreg 30 3.2 Mechanical Properties Of IMA/M12E Carbon Fiber Prepreg 31 3.3 Specimen Parameters And Quantity For Flat Specimens 34 3.4 Specimen Parameters And Quantity For L-Shaped Specimens With Two
Different Orientations Of Plies 34
xi
NO TABLE PAGES
4.15 Average Measurement Of 500×500 mm2 (8 Plies) Flat Specimen 57 4.16 Average Deviation Data Of 500×500 mm2 (8 Plies) Flat Specimen 58 4.17 Average Measurement Of 500×500 mm2 (16 Plies) Flat Specimen 58 4.18 Average Deviation Data Of 500×500 mm2 (16 Plies) Flat Specimen 58 4.19 Average Warpage Value Experienced By The 30° L-Shaped Specimen
From Its Side View 61
4.20 Average Warpage Experienced By The 30° L-Shaped Specimen From Its
Top View 61
4.21 Average Warpage Value Experienced By The 45° L-Shaped Specimen
From Its Side View 63
4.22 Average Warpage Experienced By The 45° L-Shaped Specimen From Its
Top View 63
4.23 Average Warpage Value Experienced By The 90° L-Shaped Specimen
From Its Side View 64
4.24 Average Warpage Experienced By The 90° L-Shaped Specimen From Its
4 LIST OF FIGURES
NO FIGURE PAGES
2.1 The Viscosity Of Unreinforced EH25 Resin Against Time With
Temperature (Oliver, 2006) 6
2.2 Thermal Expansion Curve For Pure Molded Phenolic Resin (Turner,
1946) 8
2.3 Thermal Expansion Curve For Phenolic Resin And Glass Fiber Mixture
(Turner, 1946) 8
2.4 Stress Gradient Between The Thickness Of The Composite (G. Fernlund,
Et Al., 2003) 9
2.5 Bidirectional And Unidirectional Ply (Advance Composite Materials,
N.D.) 11
2.6 Quasi-Isotropic Ply Orientation(Advance Composite Materials, N.D.) 11 2.7 L-Shaped Composite And C-Shaped Composite With 90° Initial Angle
(G. Fernlund, Et Al., 2002) 12
2.8 L-Shaped Composite Spring-In After Curing (G. Fernlund, Et Al., 2002) 13 2.9 C-Shaped Composite Spring-In After Curing (G. Fernlund, Et Al., 2002)
13 2.10 Comparison Between One-Hold Cycle And Two-Hold Cycle (Albert &
Fernlund, 2002) 14
2.11 Comparison Of The Effect Of Type Of Surface Condition On The
Measured Spring-In (Albert & Fernlund, 2002) 15
2.12 Coordinate Measuring Machine (CMM) 16
xiii
NO FIGURE PAGES
2.15 3D Scanner 21
2.16 (A) Design Compensation, (B) Assembly Compensation, (C) Mold Geometry Compensation (G. Fernlund, Et Al., 2003) 26
3.1 Flow Chart Of The Project 28
3.2 Cure Cycle For The Manufacturing Of The Specimens 33
3.3 300×300 mm2 Flat Specimen 35
3.4 500×500 mm2 Flat Specimen 35
3.5 30° L-Shaped Specimen 36
3.6 45° L-Shaped Specimen 36
3.7 90° L-Shaped Specimen 36
3.8 3D Scanner 37
3.9 Material Used, (A) Spray Developer And (B) Self-Adhesive
Reinforcement Rings 38
3.10 The Specimen After The Adhesive Ring And Developer Spray Are
Applied 38
3.11 (A) Laser Pointers At The Initial Distance And (B) The Merging Of Two Laser Points At The Optimum Distance (Right) 39 3.12 (A) Brightness Indication At The Lowest, (B) At Optimum And (C) At
The Highest (Right) 40
3.13 (A) Example Of Part Scanned And (B) Example Of Several Parts
Scanned For Forming The Section Of The Specimen 41 3.14 (A) Merging Process By Selecting Three Identical Points, (B) When Both Parts Are Merged, And (C) Alignment Process Is Carried Out 42 3.15 (A) Scanned Parts Form Sections Of The Specimen And (B) Full
Specimen Image For Flat Specimens 43
3.16 (A) Scanned Parts Form Sections Of The Specimen And (B) Full
Specimen Image For L-Shaped Specimens 43
3.17 Flat Specimen Is Placed On Top Of The Recreated Tool With Clear View
Of Springback Deformation 44
3.18 Vertical Line Connecting The Surface Of The Tool And The Inner
NO FIGURE PAGES
3.19 Dimension Of The Line Which Represents The Amount Of Springback
Deformation 45
3.20 Tool Model For 30° L-Shaped Specimen 47
3.21 Tool Model For 45° L-Shaped Specimen 47
3.22 Tool Model For 90° L-Shaped Specimen 48
3.23 Example Of Side View Measurement Of 45° L-Shaped Specimen 48 3.24 Example Of Top View Of The 45° Specimen To Obtain The Side
Measurements 49
4.1 Graph Of 300×300 mm2 Flat Specimens With (A) 4 Plies (B) 8 Plies And
(C) 16 Plies 53
4.2 Graph Of 400×400 mm2 Flat Specimen With (A) 4 Plies (B) 8 Plies And
(C) 16 Plies 56
4.3 Graph Of 500×500 mm2 Flat Specimens With (A) 4 Plies (B) 8 Plies
And (C) 16 Plies 59
4.4 Numbering Of Different Points From The Side View 60 4.5 Different Points Along The Longitudinal Axis 61 4.6 Tabulation Of Average Warpage Experienced By 30° L-Shaped
Specimen At Different Point For Side View And Top View 62 4.7 Tabulation Of Average Warpage Experienced By 45° L-Shaped
Specimen At Different Point For Side View And Top View 64 4.8 Tabulation Of Average Warpage Experienced By 90° L-Shaped
Specimen At Different Point For Side View And Top View 66 5.1 The Evolution Of Maximum Warpage Experienced Against Number Of
Plies For Different Specimen Size 68
5.2 The Evolution Of The Normalized Maximum Warpage Against Number
Of Plies 69
5.3 The Evolution Of Maximum Warpage Experienced Against Length Of
Specimen At Different Thickness 70
5.4 The Evolution Of Normalized Maximum Warpage Against The Length
xv
NO FIGURE PAGES
5.5 The Evolution Of Maximum Spring-In Warpage Experienced Against
The Angle Of Specimen 71
5.6 Plot Of Measured Spring-In Angle Against Part Angle (Radford &
5 LIST OF ABBREVIATIONS
CAD Computer Aided Drawing CFRP Carbon Fiber Reinforced Plastic CMM Coordinate Measuring Machine CTE Coefficient of Thermal Expansion FEP Fluorinated Ethylene Propylene MCU Master Control Unit
PTFE Polytetrafluoroethylene UD Unidirectional
xvii
6 LIST OF APPENDICES
NO TITLE PAGE
1 CHAPTER 1
INTRODUCTION
1.1 BACKGROUND
Carbon fiber reinforced plastic (CFRP) is a complex profile of a polymer bonded to carbon fiber. This composite exhibits a very high strength to weight ratio and coped with high rigidity makes an ideal application in many industries such as aerospace, automotive, motor racing and sports. The wings of an Airbus and the body frame of a competition bike are examples where CFRP is useful to give great strength and yet remain light weight. The fusion of carbon fiber and resin is done through curing process. Curing process refers to the hardening of a polymer material achieved through cross linkage of polymer chains. Curing process is done with the aid of heat, electron beams, chemical additives, or even ultraviolet radiation. In the rubber industry, curing of rubber is known as vulcanization. There are several ways to induct a curing process of CFRP.
2
After undergoing curing process, the CFRP induces a permanent deformation known as the springback. Such deformation from the desired shape causes impediments during the assembly process and higher scraps rate. Even if the deformed parts were joined by force, the level of the internal stress will further increase and thus shorten the life expectancy of the component. Deep understanding of springback phenomena is required to produce quality components to accommodate high manufacturing rate for the production of modern aircraft such as the Airbus A320. Springback deformation occurs due to the stress build up during the crystallization of the resin within the composite. Therefore, warpage acts onto the composite after curing process. Based on previous research, three different mechanisms were identified as the source of the stress generated by the curing process. Those mechanisms are chemical reaction, thermal condition and finally the interaction between the tool and the laminate.
Experimental parameters which play an important role on the springback are divided into two categories which are intrinsic parameters and extrinsic parameters. Intrinsic constraints refer to the physical parameters of the laminate composite such as the length, thickness, number of plies and shape. Extrinsic constrains on the other hand denotes manufacturing process parameters such as surface condition, tool material, cure cycle and pressure of the autoclave.
1.2 PROBLEM STATEMENT
1.3 OBJECTIVE
The investigation on the springback deformation of composite material after curing process is done with several objectives in this project. Those objectives are: 1) To measure the springback deformation of the composite material after
undergoing curing process using 3D scanner.
2) To determine the effect of the thickness, dimension and angle of the composite material on the springback deformation after undergoing curing process.
1.4 SCOPE
The following statements are the scopes of this project: 1) CFRP specimens are L shaped and flat plate.
2) 3D scanner is used to scan the specimen to convert into computer aided design file.
2 CHAPTER 2
LITERATURE REVIEW
2.1 INTRODUCTION
In this chapter, reviews of pass studies from journals were made. Literature review is essentially examined according to the sources and described to justify the statements with proof of research or study in related subject. For this research, the phenomena of springback deformation, method used for measuring, and ways to control springback deformation are discussed.
2.2 PHENOMENON OF SPRINGBACK DEFORMATION
2.2.1 Causes of Springback Deformation
The main cause of springback phenomena is due to the stress build up during the curing process. In return, the stress induces warpage onto the composite material during the cooling stage after coming out of the autoclave chamber (Safarabadi & Shokrieh, n.d.). According to the past investigations, three main mechanisms were identified as the cause of the stress generated during curing process. Those mechanisms are chemical reactions (Oliver, 2006), thermal reactions (Parlevliet, Bersee, & Beukers, 2007) and interaction between tool and the laminate (Twigg, Poursartip, & Fernlund, 2003).
