SIMULATION PERFORMANCE OF LOW DAMAGE BASE CONNECTION ON ABAQUS MAHDI ...

27 Pages·2017·0.48 MB·English

SIMULATION PERFORMANCE OF LOW DAMAGE BASE
CONNECTION ON ABAQUS

MAHDI HATAMI

A project report submitted in partial fulfillment of the
requirements for the award of the degree of
Master of Engineering (Civil-Structure)

Faculty of Civil Engineering
Universiti Teknologi Malaysia

Jun 2014
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Specially dedicated to my family and faithful and my friends
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ACKNOWLEDGEMENTS

First and foremost, I would like to express my sincerest gratitude and
appreciation to my supervisor, Assoc. Prof. Dr. Suhaimi Abubakar for his worthwhile
guidance throughout this project. His wide knowledge and his expert advice during the
period I have been carrying out this research, has been of great value for me. His
invaluable comments, kind consideration, encouragement and support have provided
a good basis present this thesis.

And then I would like to thanks who support me morally to finish my report.
Their precious opinion is useful for me to have an idea in completing this report.
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ABSTRACT

Current design codes can provide life safety performance level based on
observations from recent earthquakes. However, buildings experience some damage
that could be very costly to recover. Low damage control systems have been developed
in recent years to minimize damage in severe earthquakes. The aim of this study is to
improve the understanding of the performance of low damage steel structures
especially in regard to column base connections and the friction connection with Grade
8.8 bolts. The study involves numerical analysis to assess the stress distribution,
displacement, deformation and reaction forces by simulation on Abaqus Finite
Element software. Outcomes include an increased understanding for low damage base
connection. To reach this objective the base connection with low damage mechanism
simulated using Abaqus software is compared with the results from welded base
connection. It was observed that on low damage base connections, the stress
distribution and yielding on main elements of structure (such as column) changed
completely. This mechanism prevents any failure on column on connection with base
plate   and   failure   transferred   to   bolts   and   connection’s   plates.   Thus,   bolts   and  
connection’s  plates can be replaced after damage.
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ABSTRAK

Kod reka bentuk semasa boleh menghasilkan tahap keselamatan hidup yang
baik berdasarkan kepada pemerhatian kejadian gempa bumi yang lepas. Walau
bagaimanapun, bangunan yang telah mengalami kerosakan boleh menjadi sangat
mahal untuk kos penyelenggaraan. Sistem kawalan rendah kerosakan telah
dibangunkan dalam tahun kebelakangan ini untuk mengurangkan kerosakan akibat
gempa bumi yang teruk. Tujuan kajian ini adalah untuk meningkatkan pemahaman
prestasi struktur keluli kerosakan rendah terutamanya berkaitan dengan sambungan
asas tiang dan sambungan geseran dengan bolt bergred 8.8. Kajian ini melibatkan
analisis berangka untuk menilai agihan tegasan, anjakan, ubah bentuk dan daya
tindakbalas menggunakan simulasi daripada perisian Unsur Terhingga Abaqus. Hasil
kajian termasuklah peningkatan pemahaman untuk sambungan asas kerosakan rendah.
Untuk mencapai matlamat ini, sambungan asas dengan mekanisme kerosakan rendah
yang disimulasi daripada perisian Abaqus adalah dibandingkan dengan keputusan
sambungan asas dikimpal. Pemerhatian ke atas sambungan asas kerosakan rendah
mendapati agihan tegasan dan alahan pada elemen-elemen utama struktur (seperti
tiang) berubah sama sekali. Mekanisme ini menghalang daripada kegagalan berlaku
pada. bahagian tiang, sebaliknya memindahkan kegagalan supaya berlaku kepada bolt
dan plat sambungan. Bolt dan sambungan plat seterusnya boleh ditukar atau digantikan
selepas berlakunya kerosakan.
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TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENTS iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF FIGURES x

1 INTRODUCTION 1
1.1 Definition of Low Damage 2
1.2 Background of Study 5
1.3 Problem Statement 9
1.4 Objective of Study 10
1.5 Scope of Study 11

2 LITERATURE REVIEW 12
2.1 Low Damage Seismic Design of Buildings 12
2.1.1 Seismic Resistant Systems 13
2.1.2 Elastic Structures 16
2.1.3 Various Types of Seismic Resistant Devices 33
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2.1.4 Passive, Active and Hybrid Systems (F. Hajjar,J. at al.,
2013) 34
2.1.5 Dampers 38
2.1.6 Elastomeric Isolators 38
2.2 Types of Devices 39
2.2.1 Metallic and Friction Dampers 39
2.2.2 Viscous and Viscoelastic Dampers 51
2.2.3 Self-Centering Dampers 52
2.2.4 Elastomeric Isolators 60
2.2.5 Sliding Devices 61
2.3 Low Damage Design of Base Connection 65
2.3.1 Base Flexibility 65
2.3.2 Behavior of Steel Moment-Resisting Frames 68
2.3.3 Theoretical Behavior of Base Plate Connection 69
2.3.4 Previous Research on Column Base Behavior and
Special 71
2.4 Modeling Details 76

3 ABAQUS SIMULATION PROCEDURE 78
3.1 Finite Element Method 83
3.2 Solution Strategy 84
3.3 Element Types 85
3.3.1 Component interaction and contact: 88
3.3.2 Analyse Procedure 89
3.4 Material Properties for the Finite Element Model 91
3.5 Define Contact 104
3.6 Applying Cyclic Load as the Displacement on Model 110

4 RESULTS AND DISCUSSION 113
5 CONCLUSION 121
REFERENCES 124
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LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Possible Target Performance Objective for Damage-
Resistant Structures (MacRae, 2010, based on Hamburger, PEER) 7
1.2 Definition of structural performance 8
1.3 Building Performance Levels and Ranges (FEMA) 9
2.1 Post-Tensioned Beam Deformation and Hysteretic Behaviour
(MacRae, 2010) 17
2.2 Slotted bolted connections (Fitzgerald et al. (1989) 18
2.3 Components and assembling of Asymmetrical Friction Connections
(AFC) 19
2.4 Flexural AFC SHJ Connection (MacRae and Clifton, 2010) 20
2.5 Asymmetric Friction Connection 21
2.6 Simplified Lateral Force-Displacement Mechanism 23
2.7 SHJ Hysteresis with Steel (S) Shims 24
2.8 Alternative SHJ Connection (MacRae and Clifton, 2010) 26
2.9 Idealized Bolt Deformation, External Horizontal Forces and
Bearing Areas on Bolt Shank. 28
2.10 External Forces on Components. 28
2.11 Components and Assembly of AFC specimens (Chanchí, (2012)). 29
2.1 HF2V Devices in Steel Moment Frames (Rodgers et al. 2010) 30
2.13 Some Possible Methods for Preventing Column Yielding 33
2.14 Some types of energy dissipating systems (Elgamal, A., 2010) 34
2.15 Structure with various control schemes. (T.T. Soong, 2002) 36
2.16 Family of earthquake protective systems. (Buckle,2000 ) 37
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2.17 Elastomeric isolator 39
2.18 Mechanism of friction dampers on bracing system 41
2.19 Mechanism of multi unit friction dampers on bracing system 41
2.20 Mechanism of multi unit friction dampers on bracing system 41
2.21 Slotted-bolt friction damper 42
2.22 Slip-friction connector with (a) asymmetric mechanism, and (b),
with symmetric mechanism. 43
2.23 Sumitmo devices 46
2.24 Different types of hysteretic dampers 48
2.25 lead extrusion dampers 49
2.26 Taylor device 50
2.27 Viscoelastic damper 52
2.28 External and internal view of EDR (Nims et al., (1993)) 55
2.29 Friction spring details 56
2.30 Applications of Unbounded Post Tensioning Tendons (Walsh
et al. 2008) 57
2.31 Concept of posttension energy dissipating steel connection: a steel
frame with posttension energy dissipating connections; b geometric
configuration and free-body diagram of exterior posttension energy
dissipating connection (Christopoulos l. , 2002 ) 58
2.32 Frictional Pendulum System 63
2.33 Exposed base plate types of behavior 74
2.34 Schematics of the three typical flexural failure modes assumed for
base connections – (a) plate bending capacity on the compression
side, (b) plate bending capacity on the tension side, and (c) anchor
rod tensile capacity (Gomez IR, 2010) 75
2.35 base connection detail with non-prying AFC 76
2.36 Modes of deformations 77
3.1 Parametric Modeling Script - Main Algorithm Diagram 79
3.2 Three main stage of analyse procedure on Abaqus 80
3.3 Non-prying model parts 82
3.4 Different kinds of 3D solid elements 87
3.5 Stress-strain behavior for a linear elastic material, such as steel,
at small strains. 92
xii
3.6 Nominal stress-strain behavior of an elastic-plastic material in
a tensile test. 92
3.7 Decomposition of the total strain into elastic and plastic components.
96
3.8 Material properties for steel 98
3.9 Material properties for steel 99
3.10 Material properties for steel 100
3.11 Material properties for steel 100
3.12 Material properties for steel 101
3.13 True stress-strain curve for steel plate C 102
3.14 Plate 20mm true stress-strain curve 103
3.15 Material properties for bolts 104
3.16: The master surface relationship with slave surface. 105
3.17 Contact algorithm in Abaqus/Standard. 107
3.18 Contact between column and baseplate. 108
3.19 Bolt  interactions  with  plate’s  holes 109
3.20 Cyclic loading regime according to ACI report T1.1-01 111
3.21 Bolt load to consider tightening load 112
4.1 Stress on welded and low damage connection on drift 4 % 114
4.2 Column & plates Displacements, rocking, uplift 115
4.3 Hysteresis curve of rigid connection 116
4.4 Hysteresis curve of Non-prying model 117
4.5 Strain energy of column flange down side curve on drift 4% 118
4.6 Equilibrium of energy and external work on whole model 119
4.7 Von mises stress on three part of one bolt as a example 119
4.8 Von mises stress on plate A1 holes 120