PERPUSTAKAAN UMP 1111 11111111111111111111111111111111111111111 1 i 0000092669 ALINEA -S FOOTBRIDGE NUR SHAFIQA BT SUHAIMI A thesis submitted in partial fulfillment of the requirements for the award of the degree of Bachelor of Civil Engineering Faculty of Civil Engineering & Earth Resources University Malaysia Pahang JUNE 2013
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PERPUSTAKAAN UMP
1111 11111111111111111111111111111111111111111 1 i 0000092669
ALINEA -S FOOTBRIDGE
NUR SHAFIQA BT SUHAIMI
A thesis submitted in partial fulfillment of the
requirements for the award of the degree of
Bachelor of Civil Engineering
Faculty of Civil Engineering & Earth Resources
University Malaysia Pahang
JUNE 2013
ABSTRACT
The purpose of this dissertation is to study a linear static analysis of truss footbridge in different shape of truss. The important of this study come out where sometimes an engineer is taking much time or difficult to choose an effectives truss shape to design in real structure. In analysis, three shapes of truss are choosing which are Warren, Pratt, and Howe truss with pinned and roller support at the end of the bridge. The design loads which are pedestrian loads are distributed to the joints on bridge deck. A total of three shapes truss with 6 modelled were investigate and analyse using ANSYS+Civi1FEM software. The analysis of all sets of trusses is dividing with two groups. The first group is all load is applied along the bridge deck for three shapes of truss footbridge. For the second group, the load is applied at the mid span of bridge deck. The analysis of all sets of trusses use the same length of the span, same loads and same height of the truss footbridge. The effective of truss shape is determined when the truss footbridge has the lowest displacement and lowest axial stress. The most effectives truss footbridge is depend on number of members and arrangement of member. All the member of the truss footbridge has compression or tension force. The truss footbridge analysis is successfully modelled using ANSYS+CivilFEM software and finite element method.
vi
ABSTRAK
TUjuan projek mi adalah untuk mengkaji statik analisis dalam pelbagai jenis bentuk jambatan kekuda.Kepentingan kajian mi adalah disebabkan oleh kadang kala jurutera mengambil masa yang lama untuk memilih dan menentukan jenis jambatan kekuda yang sesuai untuk dibina.Dalam kajian ini,tiga jenis jejantas kekuda diplilih iaitu Warren,Pratt dan Howe dengan sokongan pin dan roda diletakkan di hujung jambatan.Beban pejalan kaki diletakkan di atas nod lantai jambatan.Sebanyak tiga benduk jambatan pejalan kaki dengan enam model telah di analisis menggunakan perisian komputer.Bagi menganalisis kajian ni,dua kumpulan telah di bahagikan.Kumpulan pertama,bebean diletakkan di sepanjang atas jambatan kekuda.Dan bagi kumpulan kedua pula,beban di letakkan di tengah dek jambatan kekuda.Analisis semua set jmbatn kekuda menggunakan saiz yang sama panjang beban yang sama dan ketinggian yang sama Kekuatn jambatan kekuda adalah bergantung kepada bilangan anggota dan susunan anggota. Semua ahli jambatan kekuda mempunyai mampatan atau daya ketegangan. Analisis jambatan kekuda berjaya dimodelkan menggunakan perisian komputer dan kaedah unsur terhingga.
VII
TABLE OF CONTENTS
Page
SUPERVISOR'S DECLARATION
STUDENT'S DECLARATION
ACKNOWLEDGEMENTS iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS viii
CHAPTER 1 INTRODUCTION
1.1 Introduction 1
1.2 Problem Statements 3
1.3 Objectives 3
1.4 Scope of Study 4
1.5 Significant of Research 4
CHAPTER 2 LITERATURE REVIEW
2.1 Introduction 5
2.2 Footbridge 6
2.2.1 Loading for Footbridge 6
2.3 Dead Load 7
2.4 Live Load 7
2.5 Material for Footbridge 8
2.6 Basic Bridge Types 8
2.6.1 Girder Bridge 8
2.6.2 Rigid Frame Bridge 9
2.6.3 Suspension Bridges 8
2.6.4 Truss Bridge 9
VIII
2.7 Truss Component 11
2.8 Tension Members 13
2.9 Compression Members 13
2.10 Internal forces on Truss Bridges 14
2.10.1 Bending Force 14
2.10.2 Shear Force 14
2.10.3 Torsional Force 14
2.10.4 Axial Force 15
2.11 Bridges Truss Displacement 15
2.12 Existing Research on Truss Bridge Analysis 15
CHAPTER 3 METHODOLOGY
3.1 Introduction 17
3.2 Ansys Modeller Software 19
3.3 Procedure in Analysis 21
3.4 Selection of Truss 22
3.4.1 Truss Shape 22
3.4.2 Truss Support 23
3.4.3 Truss Size 25
3.4.4 Determination of Load 22
3.5 Development of Truss Equation 22
3.6 Analysis of Truss Footbridge Using ANSYS 26
3.6.1 Preprocessing 26
3.6.2 Solution 27
3.6.3 Preprocessing 27
CHAPTER 4 RESULTS AND DISCUSSION
4.1 Introduction 29
4.2 Results (Load Apply along Bridge Deck) 30
ix
x
4.2.1 Case 1: Warren Truss 30
4.2.2 Case 2: Pratt Truss 31
4.2.3 Case 3: Howe Truss 32
4.3 Compression and Tension Forces(Load Apply along Bridge Deck) 33
4.4 Comparison Displacement with Manual Calculation 33
4.4.1 Pratt Truss (Load Apply along Bridge Deck ) 33
4.4.1.1 Displacement 33
4.4.2 Howe Truss (Load Apply along Bridge Deck) 38
4.4.2.1 Displacement 38
4.5 Results (Load Apply at Mid Span on Bridge Deck) 39
4.5.1 Case 4: Warren Truss 39
4.5.2 Case 5: Pratt Truss 40
4.5.3 Case 6: Howe Truss 42
4.6 Compression and Tension Forces(Load Apply Mid Span on Bridge Deck )42
4.7 Truss Analysis 46
4.7.1 Combination of Case (Load Apply along Bridge Deck) 46
4.7.1.lStress Analysis 46
4.7.1.2 Displacement Analysis(x axis) 47
4.7.1.3 Displacement Analysis(y axis) 48
4.7.2 Combination of Case (Load Apply at Mid Span on Bridge Deck) 49
4.7.2.1 Stress Analysis 49
4.7.2.2 Displacement Analysis(x axis) 51
4.7.2.3 Displacement Analysis(y axis) 52
CHAPTER 5 CONCLUSION AND RECOMMENDATION
5.1 Summary
5.2 Conclusion Based On Obectives 55
5.2.1 Objective 1 55
5.2.2 Objective 2 55
5.3 Recommendation 56
REFERENCES 57
xi
LIST OF TABLES
Table No. Title Page
3.1 Truss bridge geometry 23
4.1 Warren Truss (Case 1) 30
4.2 Pratt Truss (Case 2) 31
4.3 Howe Truss(Case 3) 32
4.4 Compression and Tension Forces 33
4.5 Displacement in x and y axis 37
4.6 Displacement in x and y axis 38
4.7 Warren Truss (Case 4) 39
4.8 Pratt Truss (Case 5) 40
4.9 Howe Truss(Case 6) 41
4.10 Compression and Tension Forces 42
4.11 Axial Stress in Truss Bridge 42
4.12 Displacement in x axis 46
4.13 Displacement in y axis 47
4.14 Axial Stress in Truss Bridge 49
4.15 Displacement in x axis 51
4.16 Displacement in y axis 52
XII
LIST OF FIGURES
Figure No. Title Page
3.1 Project Flow 17
3.2 ANSYS modeler 18
3.3 Modeling Procedure 19
3.4 Warren Truss 21
3.5 Pratt Truss 21
3.6 Howe Truss 22
4.1 Warren Truss (Case 1) 34
4.2 Pratt Truss (Case 2) 35
4.3 Howe Truss(Case 3) 36
4.4 Warren Truss (Case 4) 43
4.5 Pratt Truss (Case 5) 44
4.6 Howe Truss(Case 6) 45
4.7 Axial Stress in Truss Bridge 46
4.8 Displacement in x axis 47
4.9 Displacement in y axis 48
4.10 Axial Stress in Truss Bridge 50
4.11 Displacement in x axis 51
4.12 Displacement in y axis 52
XIII
LIST OF SYMBOLS
NED The tensile force from the design value
The design tension resistance of the cross section.
NU,Rd Design ultimate resistance of the net cross section
A Area of the cross section
F Ultimate strength force
Resistance of cross section in tension to fracture
F Ultimate strength force
MO Resistance of cross section whatever the class
xiv
LIST OF APPENDICES
Appendices Title Page
A Results for Case 1 53
B Results for Case 2 55
C Results for Case 3 57
D Results for Case 4 59
E Results for Case 5 61
F Results for Case 6 63
G Manual Calculation for Howe Truss 65
xvi
LIST OF ABBREVIATIONS
xv
AASHTO American Association of State Highway and Transportation Officials.
CHAPTER 1
INTRODUCTION
1.1 INTRODUCTION
A bridge is basically used to allow crossing over obstacles which are impossible
or too dangerous to travel through such as river, and road. The lack of bridge or the
failure of one can cause serious traffic congestion to the country. Design of bridges are
depends on the nature of the terrain where the bridge is constructed, the material used
and the function of the bridge. The elements of a bridge can be classified into two
primary components which are substructure and the superstructure.
In a bridge system, bridge substructure includes all foundation elements such as