CONTENTS
Preface
Notation
Chapter 1: Behaviour of Semirigid Frames
1.1 Introduction 1
1.2 Frame classification 2
1.3 Influence of joint behaviour on unbraced frame response 6
1.2.1 Simplified model 6
1.3.2 Period of vibration 8
1.3.3 Frame sensitivity to second-order effects 9
1.3.4 Inelastic behaviour 11
1.4 Influence of joint behaviour on braced frame response 19
1.5 Classification of joints 21
1.6 References 35
Chapter 2: Modelling of Joint Behaviour
2.1 Introduction 38
2.2 Methods for modelling rotational behaviour 41
2.3 Mathematical representation of moment-rotation curve 44
2.3.1 Generality 44
2.3.2 Stiffness, resistance and shape factor based formulations 45
2.3.3 Curve Fitting by regression analysis 56
2.4 Methods for predicting moment-rotation curves 58
2.4.1 Generality 58
2.4.2 Empirical models 58
2.4.3 Analytical models 67
2.4.4 Mechanical models 73
2.4.5 Finite element analysis 77
2.4.6 Experimental testing 78
2.5 References 79
Chapter 3: Welded Connections
3.1 Introduction 84
3.2 Column web in shear 88
3.3 Column web in compression 96
3.3.1 Crushing resistance 96
3.3.2 Buckling resistance 100
3.3.3 Initial stiffness 103
3.4 Column web in tension 104
3.4.1 Resistance 104
3.4.2 Initial Stiffness 106
3.5 Considerations on local stress interaction 106
3.6 Column flange in bending 110
3.7 Beam flange and web in compression 114
3.8 Comparison with experimental data 114
3.9 Influence of strain-hardening 119
3.10 Worked examples 125
3.10.1Unstiffened external joint 125
3.10.2 Stiffened external joint 130
3.11References 132
Chapter 4: Basic Component of Bolted Connections
4.1 Introduction 135
4.2 Axial strength of bolted T-stubs 137
4.2.1 Basic formulations 137
4.2.2 The influence of moment-shear interaction 143
4.3 Axial stiffness of bolted T-stubs 149
4.3.1 Basic principles 149
4.3.2 Description of specimens and testing devices 152
4.3.3 Experimental results 157
4.3.4 Axial stiffness prediction of non-preloaded T-stubs 160
4.3.5 Axial stiffness prediction of preloaded T-stubs 164
4.4 References 170
Chapter 5: Bolted End-Plate Connections
5.1 Introduction 172
5.2 Prediction of flexural resistance 177
5.2.1 Column web in shear 177
5.2.2 Column web in compression 177
5.2.3 Column flange in bending 177
5.2.4 End plate in bending 182
5.2.5 Column web in tension 184
5.2.6 Beam flange and web in compression 185
5.2.7 Beam web in tension 185
5.2.8 Procedure for evaluating the joint flexural resistance 185
5.2.9Comparison with experimental results 189
5.3 Prediction of initial rotational stiffness 190
5.3.1 Generality 190
5.3.2 Column web in shear 192
5.3.3 Column web in compression 192
5.3.4 Column web in tension 192
5.3.5 Column flange in bending and end plate in bending 195
5.3.6 Bolt row in tension 195
5.3.7 Comparison with experimental data 196
5.3.8 The influence of the bolt preloading 199
5.4 Moment-rotation curve 200
5.5 Worked examples 206
5.5.1Geometrical and mechanical properties 206
5.5.2 Initial rotational stiffness 207
5.5.3 Flexural resistance 212
5.6 References 219
Chapter 6: Bolted Connections with Angles
6.1 Introduction 222
6.2 Prediction of the flexural resistance 223
6.2.1 Component identification 223
6.2.2 Column web in shear 225
6.2.3 Column web in compression 226
6.2.4 Column web in tension and column flange in bending 227
6.2.5 Top angle in bending 227
6.2.6 Web angles in bending 234
6.2.7 Bolts in tension 242
6.2.8 Bolts in shear 242
6.2.9 Plates in bearing 243
6.2.10 Plate intension 243
6.2.11 Plate in compression 245
6.2.12 Beam web in tension 245
6.2.13 Beam flange and web in compression 245
6.3 Operative steps 246
6.4 Comparison with experimental data 248
6.5 Simplified procedure 253
6.6 Prediction of rotational stiffness 254
6.6.1 Identification of deformation sources 254
6.6.2 Column web in shear 258
6.6.3 Column web in compression 258
6.6.4 Column web in tension 259
6.6.5 Column flange in bending 259
6.6.6 Bolt row in tension 259
6.6.7 Angle in bending 260
6.6.8 Bolts in shear 263
6.6.9 Plate in bearing 263
6.6.10 The influence of bolt preloading 263
6.6.1 1 Comparison with experimental data 265
6.7 Worked example 267
6.7.1 Flexural resistance 267
6.7.2 Rotational stiffness 279
6.8 References 286
Chapter 7: JMRC - Computer Program for Evaluating the Joint Moment Rotation Curve
7.1 Analysed joint typologies 288
7.2 Description of input data 288
7.2.1 Generality 288
7.2.2 Basic joint data 289
7.2.3 Data for connecting elements of welded connections 296
7.2.4 Data for connecting elements of end-plate connections 297
7.2.5 Data for connecting elements of angle connections 298
7.3 Examples of input data files 301
7.3.1 Welded connections 301
7.3.2 End plate connections 301
7.3.3 Connections with angles 302
7.4 Adopted formulations 303
7.5 References 308
Chapter 8: Design of Extended End-Plate Connections for Braced Frames
8.1 Introduction 309
8.2 Behaviour and design of end-plate connections 312
8.2.1 Parametric analysis 312
8.2.2 Flexural resistance versus rotational stiffness relation 315
8.2.3 End-plate thickness versus rotational stiffness relation 319
8.2.4 Design abaci 326
8.3 Design procedure for braced frames 332
8.3.1 Design conditions 332
8.3.2 Design algorithm 334
8.4 Applications 338
8.5 References 340
Chapter 9: Ductility of Connections
9.1 Introduction 342
9.2 Plastic rotation supply of the beam-joint system 344
9.3 Welded connections 349
9.4 Bolted connections 351
9.4.1 Generality 351
9.4.2 Basis of the theoretical approach 352
9.4.3 Material constitutive law 354
9.4.4 Moment-curvature relationship 355
9.4.5 Failure modes 357
9.4.6 Ultimate plastic displacement for type-1 mechanism 357
9.4.7 Ultimate plastic displacement for type-2 mechanism 361
9.4.8 Ultimate plastic displacement for type-3 mechanism 370
9.4.9 Bolt plastic deformation 371
9.4.10 Prediction of the force-displacement curve 371
9.4.11 Comparison with experimental evidence 380
9.5 Parameters affecting ductility 384
9.6 Ultimate plastic rotation of connections with angles 385
9.7 Ultimate plastic rotation of end-plate connections 392
9.8 References 395
Chapter 10: Cyclic Behaviour of Beam-to-Column Joints
10.1 Introduction 399
10.2 Experimental evidence 402
10.3 Low cycle fatigue 412
10.4 Modelling of cyclic response 426
10.4.1 Model classification 426
10.4.2 Mathematical models 427
10.4.3 Mechanical models 433
10.4.4 Cyclic behaviour of bolted T-stubs 438
10.5 References 444
Chapter 11: Seismic Design of Semirigid Frames
11.1 Introduction 449
11.2 Connection and panel zone design 453
11.2.1 Connection design 453
11.2.2 Panel zone design 454
11.3 Second-order plastic design of moment resisting frames 457
11.3.1 Background on capacity design 457
11.3.2 Location of plastic hinges 460
11.3.3 Notation 463
11.3.4 Mechanism equilibrium curves 466
11.3.5 Global type mechanism 468
11.3.6 Type-1 mechanisms 468
11.3.7 Type-2 mechanisms 469
11.3.8 Type-3 mechanisms 469
11.3.9 Design conditions for failure mode control 470
11.3.10 Conditions to avoid type-1 mechanisms 471
11.3.11 Conditions to avoid type-2 mechanisms 474
11.3.12 Conditions to avoid type-3 mechanisms 476
11.3.13 Technological conditions 477
11.3.14 Evaluation of the axial load in the columns at the collapse state 478
11.3.15 Design algorithm 478
11.4 The influence of beam-to-column joints 481
11.4.1 Preliminary remarks 481
11.4.2 Evaluation of joint rotational stiffness 482
11.4.3 Checking serviceability requirements 483
11.4.4 Design procedure 486
11.5 Parametric analyses 491
11.6 Dynamic inelastic analyses 492
11.7 References 494