Year: 2017 Language: english Author: Mandal, Nisith Ranjan Genre: Учебное пособие Publisher: Springer Series on Naval Architecture, Marine Engineering, Shipbuilding and Shipping Издание: Springer Singapore ISBN: 978-981-10-2955-4 Format: PDF Quality: eBook Number of pages: XV, 314 Description: This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters.The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures.With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and forming of plates and sections are explained. The concept of line heating for plate bending is introduced.Welding power source characteristics, metal transfer mechanisms, welding parameters and their effects on the fusion zone, weld deposit, and weld bead profile are discussed in detail. Various fusion welding methods, MMAW, GMAW, SAW, Electroslag welding and Electrogas welding and single side welding are explained in detail. Friction stir welding as one of the key methods of solid state welding as applied to aluminum alloys is also addressed.The mechanisms of residual stress formation and distortion are explained in connection with stiffened panel fabrication, with an emphasis on weld induced buckling of thin panels. Further, the basic principles of distortion prevention, in-process distortion control and mitigation techniques like heat sinking, thermo-mechanical tensioning etc. are dealt with in detail.In its final section, the book describes in detail various types of weld defects that are likely to occur, together with their causes and remedial measures. The nondestructive testing methods that are most relevant to ship construction are explained. Lastly, a chapter on accuracy control based on statistical principles is included, addressing the need for a suitable mechanism to gauge the ranges of variations so that one can quantitatively target the end product accuracy. Additional info: Engineering, Mechanical Engineering,Marine Engineering
Contents
1 Introduction to Ships ..................................... 1 1.1 Ship Types ........................................ 2 1.2 Basic Features...................................... 3 References............................................... 19 2 Characteristics of Shipbuilding Industry ...................... 21 3 Structural Requirement ................................... 25 3.1 Longitudinal Strength ................................ 27 3.2 Transverse Strength.................................. 29 3.3 Torsional Strength................................... 29 3.4 Local Strength ..................................... 30 3.5 Structural Arrangement ............................... 30 3.6 Framing System .................................... 33 3.6.1 Longitudinal Framing System .................. 33 3.6.2 Transverse Framing System.................... 36 4 Basic Structural Components............................... 39 4.1 Longitudinal and Transverse Members ................... 39 4.2 Girders and Transverses .............................. 40 4.2.1 Centre Girder............................... 41 4.2.2 Side Girder ................................ 41 4.2.3 Hatch Side Girder ........................... 42 4.2.4 Hatch End Beam ............................ 42 4.2.5 Deck Transverse ............................ 42 4.3 Stringers .......................................... 44 4.4 Floors ............................................ 44 4.4.1 Plate Floor................................. 45 4.4.2 Bracket Floor............................... 45 4.4.3 Water Tight Floor ........................... 46 4.5 Brackets .......................................... 46 References............................................... 48 ix 5 Structural Subassemblies .................................. 49 5.1 Flat Stiffened Panel.................................. 50 5.2 Curved Stiffened Panel ............................... 51 5.3 Bulkheads......................................... 51 5.3.1 Transverse Water Tight Bulkhead ............... 52 5.3.2 Non Water Tight Bulkheads ................... 55 5.4 Decks and Shells ................................... 56 5.4.1 Main Deck and Lower Deck ................... 56 5.4.2 Side Shell ................................. 58 5.4.3 Inner Bottom Plating ......................... 58 5.4.4 Bottom Shell ............................... 59 6 Structural Assemblies ..................................... 61 6.1 Double Bottom Construction .......................... 61 6.2 Wing Tanks ....................................... 63 6.3 Duct Keel ......................................... 65 6.4 End Construction ................................... 66 6.4.1 Fore End Construction........................ 66 6.4.2 Aft End Construction......................... 70 6.5 Rudders........................................... 74 6.6 Stern Tube ........................................ 75 6.7 Shaft Boss and ‘A’ Bracket............................ 76 7 Midship Sections ......................................... 77 7.1 General Cargo Carrier................................ 78 7.2 Bulk Carrier/OBO Carrier............................. 79 7.3 Container Ship ..................................... 81 7.4 Oil Tanker ........................................ 81 7.5 RO-RO Ship ....................................... 83 References............................................... 84 8 Structural Alignment and Continuity ........................ 85 8.1 Structural Alignment................................. 85 8.2 Structural Continuity................................. 88 Reference ............................................... 90 9 Material of Construction................................... 91 9.1 Steels ............................................ 93 9.1.1 Normal Strength Steel ........................ 95 9.1.2 High Strength Steel .......................... 96 9.1.3 Wear-Resistant Applications ................... 98 9.1.4 Stainless Steels ............................. 98 9.2 Aluminum Alloys ................................... 100 9.2.1 Aluminum Alloy in Shipbuilding Applications ..... 102 9.3 Fibre Reinforced Composites .......................... 106 References............................................... 109 x Contents 10 Steel Material Preparation ................................. 111 10.1 Straightening and Stress Relieving ...................... 112 10.2 Surface Dressing—Mill Scale Removal .................. 112 10.2.1 Shot Blasting ............................... 113 10.2.2 Acid Pickling............................... 114 11 Plate Cutting ............................................ 117 11.1 Mechanical Process.................................. 117 11.1.1 Mechanical Shearing ......................... 118 11.1.2 Water Jet .................................. 118 11.2 Thermal Process .................................... 122 11.2.1 Oxy-Fuel Flame Cutting ...................... 123 11.2.2 Plasma Arc Cutting .......................... 125 11.2.3 Laser Cutting ............................... 130 References............................................... 132 12 Plate and Section Forming ................................. 135 12.1 Mechanical Methods................................. 136 12.1.1 Roller Bending and Hydraulic Press ............. 136 12.1.2 Universal Press for Plate Bending ............... 138 12.2 Line Heating ....................................... 139 12.2.1 Compound Curved Surface Generation ........... 141 12.2.2 Heating Path Generation ...................... 143 12.2.3 Types of Heat Sources Used in Line Heating ...... 143 References............................................... 144 13 Fusion Welding Power Source .............................. 145 13.1 Types and Characteristics ............................. 146 13.1.1 Constant Current Power Source ................. 147 13.1.2 Constant Voltage Power Source................. 149 13.1.3 Pulsed Mode Power Source .................... 150 13.1.4 Inverter Power Supply ........................ 151 13.2 Metal Transfer Mechanism ............................ 152 13.2.1 Short Circuiting Transfer ...................... 152 13.2.2 Globular Transfer............................ 153 13.2.3 Spray Transfer .............................. 154 13.2.4 Pulsed Transfer ............................. 156 References............................................... 157 14 Welding Parameters ...................................... 159 14.1 Welding Current .................................... 160 14.2 Welding Arc Voltage ................................ 161 14.3 Welding Speed ..................................... 163 14.4 Electrode Feed Speed ................................ 164 14.5 Electrode Extension ................................. 164 14.6 Electrode Diameter .................................. 165 Contents xi 14.7 Electrode Orientation ................................ 166 14.8 Electrode Polarity ................................... 167 14.9 Shielding Gas Composition............................ 168 14.10 Marangoni Convection ............................... 169 14.11 Cooling Rate and HAZ............................... 170 References............................................... 174 15 Fusion Welding Methods .................................. 175 15.1 Manual Metal Arc Welding ........................... 176 15.1.1 Types of Electrodes.......................... 177 15.1.2 Basic Features .............................. 180 15.1.3 Operating Variables.......................... 181 15.2 Gas Metal Arc Welding .............................. 182 15.2.1 Process Characteristics........................ 182 15.2.2 Metal Transfer Characteristics .................. 183 15.2.3 Operating Variables.......................... 185 15.2.4 Shielding Gases............................. 188 15.3 Submerged Arc Welding.............................. 191 15.3.1 Process Characteristics........................ 192 15.3.2 Operating Variables.......................... 193 15.3.3 Flux ...................................... 197 15.3.4 Estimation of Welding Parameters............... 198 15.3.5 Cracks in Submerged Arc Welds................ 200 15.4 Electrogas Welding.................................. 201 15.4.1 Salient Features ............................. 202 15.4.2 Process Characteristics........................ 202 15.4.3 Application and Welding Performance............ 206 15.5 Electroslag Welding ................................. 207 15.5.1 Process Characteristics........................ 208 15.5.2 Operating Variables.......................... 209 15.5.3 Merits and Limitations........................ 212 15.5.4 Application ................................ 212 15.6 Single Side Welding ................................. 213 15.6.1 Process Variables............................ 213 15.6.2 Backing Strip............................... 214 15.7 Multi Electrode Welding.............................. 217 15.7.1 Characteristic Features........................ 217 15.7.2 Salient Features ............................. 219 References............................................... 219 16 Solid State Welding....................................... 221 16.1 Friction Stir Welding ................................ 222 16.1.1 Features of FSW Joint ........................ 223 16.1.2 Tool Geometry ............................. 224 16.1.3 Tool Material............................... 225 xii Contents 16.1.4 Heat Generation............................. 225 16.1.5 Basic FSW Metallurgy of Aluminum Alloy ....... 230 16.1.6 Defects and Their Detection ................... 231 16.1.7 Merits and Limitations of FSW ................. 232 References............................................... 233 17 Welding Residual Stress and Distortion....................... 235 17.1 Key Issues ........................................ 239 17.1.1 Role of Designers ........................... 239 17.1.2 Degree of Initial Deformation .................. 240 17.1.3 Plate Handling .............................. 240 17.1.4 Steel Cutting ............................... 240 17.1.5 Stiffener Welding............................ 241 17.2 Residual Stresses.................................... 241 17.2.1 Plastic Strain ............................... 244 17.3 Distortion Mechanism................................ 247 17.3.1 Shrinkage Due to Butt Welds .................. 248 17.3.2 Longitudinal Bending (Bowing) in Built-up Girders........................... 251 17.3.3 Buckling Due to Welding ..................... 251 17.3.4 Distortions in Ship Hull Units .................. 252 17.3.5 Shrinkage of Hull Units....................... 252 17.3.6 Buckling of Shell and Deck Panels .............. 258 References............................................... 260 18 Distortion Control and Mitigation ........................... 263 18.1 Distortion Control Through Design...................... 264 18.2 Distortion Control Through Fabrication Technique .......... 268 18.3 Heat Input......................................... 269 18.4 Heat Sinking....................................... 270 18.5 Thermo-Mechanical Tensioning ........................ 271 18.5.1 TMT Model................................ 273 18.6 Weld Sequencing ................................... 275 References............................................... 281 19 Welding Defects.......................................... 283 19.1 Lack of Penetration.................................. 284 19.2 Lack of Fusion ..................................... 285 19.3 Undercutting ....................................... 286 19.4 Porosity........................................... 286 19.5 Weld Cracks....................................... 288 19.6 Slag Inclusion ...................................... 291 References............................................... 292 Contents xiii 20 Nondestructive Testing .................................... 293 20.1 Visual Inspection ................................... 294 20.2 Dye Penetrant Testing................................ 294 20.3 Magnetic Particle Testing ............................. 295 20.4 Radiographic Testing ................................ 296 20.5 Ultrasonic Testing................................... 297 20.6 Acoustic Emission Testing ............................ 298 Reference ............................................... 299 21 Accuracy Control ........................................ 301 21.1 Accuracy Control System ............................. 303 21.2 Control Charts ..................................... 304 21.3 Accuracy Control Planning ............................ 309 21.4 Accuracy Control Standardization....................... 310 21.5 Setting Accuracy Standards............................ 311 21.6 Factors Leading to Dimensional Error ................... 312 21.7 Self Check ........................................ 313 References............................................... 314
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Ship Construction and Welding
Year: 2017
Language: english
Author: Mandal, Nisith Ranjan
Genre: Учебное пособие
Publisher: Springer Series on Naval Architecture, Marine Engineering, Shipbuilding and Shipping
Издание: Springer Singapore
ISBN: 978-981-10-2955-4
Format: PDF
Quality: eBook
Number of pages: XV, 314
Description: This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters.The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures.With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and forming of plates and sections are explained. The concept of line heating for plate bending is introduced.Welding power source characteristics, metal transfer mechanisms, welding parameters and their effects on the fusion zone, weld deposit, and weld bead profile are discussed in detail. Various fusion welding methods, MMAW, GMAW, SAW, Electroslag welding and Electrogas welding and single side welding are explained in detail. Friction stir welding as one of the key methods of solid state welding as applied to aluminum alloys is also addressed.The mechanisms of residual stress formation and distortion are explained in connection with stiffened panel fabrication, with an emphasis on weld induced buckling of thin panels. Further, the basic principles of distortion prevention, in-process distortion control and mitigation techniques like heat sinking, thermo-mechanical tensioning etc. are dealt with in detail.In its final section, the book describes in detail various types of weld defects that are likely to occur, together with their causes and remedial measures. The nondestructive testing methods that are most relevant to ship construction are explained. Lastly, a chapter on accuracy control based on statistical principles is included, addressing the need for a suitable mechanism to gauge the ranges of variations so that one can quantitatively target the end product accuracy.
Additional info: Engineering, Mechanical Engineering,Marine Engineering
Contents
1 Introduction to Ships ..................................... 11.1 Ship Types ........................................ 2
1.2 Basic Features...................................... 3
References............................................... 19
2 Characteristics of Shipbuilding Industry ...................... 21
3 Structural Requirement ................................... 25
3.1 Longitudinal Strength ................................ 27
3.2 Transverse Strength.................................. 29
3.3 Torsional Strength................................... 29
3.4 Local Strength ..................................... 30
3.5 Structural Arrangement ............................... 30
3.6 Framing System .................................... 33
3.6.1 Longitudinal Framing System .................. 33
3.6.2 Transverse Framing System.................... 36
4 Basic Structural Components............................... 39
4.1 Longitudinal and Transverse Members ................... 39
4.2 Girders and Transverses .............................. 40
4.2.1 Centre Girder............................... 41
4.2.2 Side Girder ................................ 41
4.2.3 Hatch Side Girder ........................... 42
4.2.4 Hatch End Beam ............................ 42
4.2.5 Deck Transverse ............................ 42
4.3 Stringers .......................................... 44
4.4 Floors ............................................ 44
4.4.1 Plate Floor................................. 45
4.4.2 Bracket Floor............................... 45
4.4.3 Water Tight Floor ........................... 46
4.5 Brackets .......................................... 46
References............................................... 48
ix
5 Structural Subassemblies .................................. 49
5.1 Flat Stiffened Panel.................................. 50
5.2 Curved Stiffened Panel ............................... 51
5.3 Bulkheads......................................... 51
5.3.1 Transverse Water Tight Bulkhead ............... 52
5.3.2 Non Water Tight Bulkheads ................... 55
5.4 Decks and Shells ................................... 56
5.4.1 Main Deck and Lower Deck ................... 56
5.4.2 Side Shell ................................. 58
5.4.3 Inner Bottom Plating ......................... 58
5.4.4 Bottom Shell ............................... 59
6 Structural Assemblies ..................................... 61
6.1 Double Bottom Construction .......................... 61
6.2 Wing Tanks ....................................... 63
6.3 Duct Keel ......................................... 65
6.4 End Construction ................................... 66
6.4.1 Fore End Construction........................ 66
6.4.2 Aft End Construction......................... 70
6.5 Rudders........................................... 74
6.6 Stern Tube ........................................ 75
6.7 Shaft Boss and ‘A’ Bracket............................ 76
7 Midship Sections ......................................... 77
7.1 General Cargo Carrier................................ 78
7.2 Bulk Carrier/OBO Carrier............................. 79
7.3 Container Ship ..................................... 81
7.4 Oil Tanker ........................................ 81
7.5 RO-RO Ship ....................................... 83
References............................................... 84
8 Structural Alignment and Continuity ........................ 85
8.1 Structural Alignment................................. 85
8.2 Structural Continuity................................. 88
Reference ............................................... 90
9 Material of Construction................................... 91
9.1 Steels ............................................ 93
9.1.1 Normal Strength Steel ........................ 95
9.1.2 High Strength Steel .......................... 96
9.1.3 Wear-Resistant Applications ................... 98
9.1.4 Stainless Steels ............................. 98
9.2 Aluminum Alloys ................................... 100
9.2.1 Aluminum Alloy in Shipbuilding Applications ..... 102
9.3 Fibre Reinforced Composites .......................... 106
References............................................... 109
x Contents
10 Steel Material Preparation ................................. 111
10.1 Straightening and Stress Relieving ...................... 112
10.2 Surface Dressing—Mill Scale Removal .................. 112
10.2.1 Shot Blasting ............................... 113
10.2.2 Acid Pickling............................... 114
11 Plate Cutting ............................................ 117
11.1 Mechanical Process.................................. 117
11.1.1 Mechanical Shearing ......................... 118
11.1.2 Water Jet .................................. 118
11.2 Thermal Process .................................... 122
11.2.1 Oxy-Fuel Flame Cutting ...................... 123
11.2.2 Plasma Arc Cutting .......................... 125
11.2.3 Laser Cutting ............................... 130
References............................................... 132
12 Plate and Section Forming ................................. 135
12.1 Mechanical Methods................................. 136
12.1.1 Roller Bending and Hydraulic Press ............. 136
12.1.2 Universal Press for Plate Bending ............... 138
12.2 Line Heating ....................................... 139
12.2.1 Compound Curved Surface Generation ........... 141
12.2.2 Heating Path Generation ...................... 143
12.2.3 Types of Heat Sources Used in Line Heating ...... 143
References............................................... 144
13 Fusion Welding Power Source .............................. 145
13.1 Types and Characteristics ............................. 146
13.1.1 Constant Current Power Source ................. 147
13.1.2 Constant Voltage Power Source................. 149
13.1.3 Pulsed Mode Power Source .................... 150
13.1.4 Inverter Power Supply ........................ 151
13.2 Metal Transfer Mechanism ............................ 152
13.2.1 Short Circuiting Transfer ...................... 152
13.2.2 Globular Transfer............................ 153
13.2.3 Spray Transfer .............................. 154
13.2.4 Pulsed Transfer ............................. 156
References............................................... 157
14 Welding Parameters ...................................... 159
14.1 Welding Current .................................... 160
14.2 Welding Arc Voltage ................................ 161
14.3 Welding Speed ..................................... 163
14.4 Electrode Feed Speed ................................ 164
14.5 Electrode Extension ................................. 164
14.6 Electrode Diameter .................................. 165
Contents xi
14.7 Electrode Orientation ................................ 166
14.8 Electrode Polarity ................................... 167
14.9 Shielding Gas Composition............................ 168
14.10 Marangoni Convection ............................... 169
14.11 Cooling Rate and HAZ............................... 170
References............................................... 174
15 Fusion Welding Methods .................................. 175
15.1 Manual Metal Arc Welding ........................... 176
15.1.1 Types of Electrodes.......................... 177
15.1.2 Basic Features .............................. 180
15.1.3 Operating Variables.......................... 181
15.2 Gas Metal Arc Welding .............................. 182
15.2.1 Process Characteristics........................ 182
15.2.2 Metal Transfer Characteristics .................. 183
15.2.3 Operating Variables.......................... 185
15.2.4 Shielding Gases............................. 188
15.3 Submerged Arc Welding.............................. 191
15.3.1 Process Characteristics........................ 192
15.3.2 Operating Variables.......................... 193
15.3.3 Flux ...................................... 197
15.3.4 Estimation of Welding Parameters............... 198
15.3.5 Cracks in Submerged Arc Welds................ 200
15.4 Electrogas Welding.................................. 201
15.4.1 Salient Features ............................. 202
15.4.2 Process Characteristics........................ 202
15.4.3 Application and Welding Performance............ 206
15.5 Electroslag Welding ................................. 207
15.5.1 Process Characteristics........................ 208
15.5.2 Operating Variables.......................... 209
15.5.3 Merits and Limitations........................ 212
15.5.4 Application ................................ 212
15.6 Single Side Welding ................................. 213
15.6.1 Process Variables............................ 213
15.6.2 Backing Strip............................... 214
15.7 Multi Electrode Welding.............................. 217
15.7.1 Characteristic Features........................ 217
15.7.2 Salient Features ............................. 219
References............................................... 219
16 Solid State Welding....................................... 221
16.1 Friction Stir Welding ................................ 222
16.1.1 Features of FSW Joint ........................ 223
16.1.2 Tool Geometry ............................. 224
16.1.3 Tool Material............................... 225
xii Contents
16.1.4 Heat Generation............................. 225
16.1.5 Basic FSW Metallurgy of Aluminum Alloy ....... 230
16.1.6 Defects and Their Detection ................... 231
16.1.7 Merits and Limitations of FSW ................. 232
References............................................... 233
17 Welding Residual Stress and Distortion....................... 235
17.1 Key Issues ........................................ 239
17.1.1 Role of Designers ........................... 239
17.1.2 Degree of Initial Deformation .................. 240
17.1.3 Plate Handling .............................. 240
17.1.4 Steel Cutting ............................... 240
17.1.5 Stiffener Welding............................ 241
17.2 Residual Stresses.................................... 241
17.2.1 Plastic Strain ............................... 244
17.3 Distortion Mechanism................................ 247
17.3.1 Shrinkage Due to Butt Welds .................. 248
17.3.2 Longitudinal Bending (Bowing)
in Built-up Girders........................... 251
17.3.3 Buckling Due to Welding ..................... 251
17.3.4 Distortions in Ship Hull Units .................. 252
17.3.5 Shrinkage of Hull Units....................... 252
17.3.6 Buckling of Shell and Deck Panels .............. 258
References............................................... 260
18 Distortion Control and Mitigation ........................... 263
18.1 Distortion Control Through Design...................... 264
18.2 Distortion Control Through Fabrication Technique .......... 268
18.3 Heat Input......................................... 269
18.4 Heat Sinking....................................... 270
18.5 Thermo-Mechanical Tensioning ........................ 271
18.5.1 TMT Model................................ 273
18.6 Weld Sequencing ................................... 275
References............................................... 281
19 Welding Defects.......................................... 283
19.1 Lack of Penetration.................................. 284
19.2 Lack of Fusion ..................................... 285
19.3 Undercutting ....................................... 286
19.4 Porosity........................................... 286
19.5 Weld Cracks....................................... 288
19.6 Slag Inclusion ...................................... 291
References............................................... 292
Contents xiii
20 Nondestructive Testing .................................... 293
20.1 Visual Inspection ................................... 294
20.2 Dye Penetrant Testing................................ 294
20.3 Magnetic Particle Testing ............................. 295
20.4 Radiographic Testing ................................ 296
20.5 Ultrasonic Testing................................... 297
20.6 Acoustic Emission Testing ............................ 298
Reference ............................................... 299
21 Accuracy Control ........................................ 301
21.1 Accuracy Control System ............................. 303
21.2 Control Charts ..................................... 304
21.3 Accuracy Control Planning ............................ 309
21.4 Accuracy Control Standardization....................... 310
21.5 Setting Accuracy Standards............................ 311
21.6 Factors Leading to Dimensional Error ................... 312
21.7 Self Check ........................................ 313
References............................................... 314
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