OUTLINE Introduction Motivation Replaceable shear link in MRFs - PDF document

٠٩ / ٠۴ / ١۴٣۶ FINITE ELEMENT INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES By: Pouya Rezazadeh (Sharif University of Technology) Kiarash M. Dolatshahi (Sharif University of Technology) M. T. Nikoukalam (Presentor) (University of Colorado Boulder) June 2015 OUTLINE • Introduction • Motivation • Replaceable shear link in MRFs • Perforated and slit shear links • Summary and conclusion M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ١

٠٩ / ٠۴ / ١۴٣۶ Introduction • Of the most favorable lateral load resisting systems are Special Moment Resisting Frames (SMRFs) due to their high ductility and energy dissipation capacity. • A minimum span-to-depth ratio of 7 in special MRFs and 5 in intermediate MRFs must be maintained (AISC 358-10) • The span-to-depth ratio in Framed Tube structures is about 3.4-4. M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Motivation V V >V >V V pb3 pb2 pb1 V V pb1 V >V pb2 pb1 M M M F F F F F F � � 2� � � � M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ٢

٠٩ / ٠۴ / ١۴٣۶ Motivation (Photo by M.T.Nikoukalam) M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Replaceable shear link in MRFs Stiffener Pls Bolted End-Plate Connection L C Beam Prefabricated in shop & shipped to site e Replaceable Shear Link • Replaceable shear link with solid web On-site bolting of replaceable link • Slit shear link • Perforated shear link M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ٣

٠٩ / ٠۴ / ١۴٣۶ Replaceable shear link in MRFs Methodology • Finite Element Modeling (Abaqus/CAE 6.13-1) 2.0 800 900 Test Test Test 600 ABAQUS ABAQUS ABAQUS 600 V n Link Shear: V (kN) 400 1.0 at Column Face (M/M pn ) Link Shear: V (kN) Normalized Moment 300 200 0 0.0 0 -200 -300 -400 -1.0 -600 V n -600 -800 -2.0 -900 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 -8 -6 -4 -2 0 2 4 6 8 -0.15 -0.10 -0.05 0.00 0.05 0.10 0.15 Inelastic Rotation: γ p (rad) Story Drift (%) Inelastic Rotation: γ P (rad) Okazaki, M.D. Engelhardt (2007) Lee et al. (2005) M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Replaceable shear link concept in MRFs Design Concept 2 1 1 θ > θ θ p p p Base shear (a)RBS 2 1 0 Drift (b)Shear Link Frame (SLF) Flexural yielding 2 Base shear 1 Shear (a)Hybrid Frame (HF) yielding 0 Drift Rapid return Collapse prevention Elastic to occupancy M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ۴

٠٩ / ٠۴ / ١۴٣۶ Replaceable shear link concept in MRFs Frames with shear fuse (a) L/d=4 (b) L/d=5 (c) L/d=7 M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES 2000 2000 2000 12 14 12 x 100000 x 100000 x 100000 Shear Link Shear Link Shear Link 1500 1500 1500 12 10 10 Shear Link Shear Link Shear Link Base Shear (kN) Base Shear (kN) Base Shear (kN) RBS RBS 1000 1000 1000 RBS 10 RBS RBS RBS Accumulative Energy Accumulative Energy Accumulative Energy 8 8 Dissipation (kN.mm) Dissipation (kN.mm) Dissipation (kN.mm) 500 500 500 8 6 0 0 0 6 6 -500 -500 -500 4 4 4 -1000 -1000 -1000 2 2 2 -1500 -1500 -1500 -2000 -2000 -2000 0 0 0 -6.0 -6.0 -6.0 0.0 0.0 0.0 -4.0 -4.0 -4.0 1.0 1.0 1.0 -2.0 -2.0 2.0 2.0 2.0 -2.0 0.0 0.0 3.0 0.0 3.0 3.0 4.0 4.0 2.0 2.0 4.0 2.0 4.0 5.0 4.0 5.0 4.0 5.0 6.0 6.0 6.0 6.0 6.0 6.0 Replaceable shear link concept in MRFs Story Drift (%) Story Drift (%) Story Drift (%) Story Drift (%) Story Drift (%) Story Drift (%) Analysis results • Shear Link Frame (SLF) 2000 2000 2000 Shear Link 1500 Shear Link 1500 1500 Shear Link Base Shear (kN) Base Shear (kN) RBS 1000 RBS 1000 Base Shear (kN) 1000 RBS 500 500 500 5.0 0 0 0 -500 -500 -500 L/D = 4 -1000 4.0 -1000 -1000 -1500 -1500 L/D = 5 -1500 (SLF) PE / (RBS) PE -2000 -2000 -2000 -6.0 -4.0 -2.0 0.0 2.0 4.0 3.0 6.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 L/D = 7 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 Story Drift (%) Story Drift (%) Story Drift (%) (I) Cyclic load-displacement curves 2.0 14 12 12 x 100000 x 100000 x 100000 12 Shear Link 10 Shear Link 10 Shear Link 10 1.0 RBS RBS RBS Accumulative Energy Accumulative Energy 8 Accumulative Energy 8 Dissipation (kN.mm) Dissipation (kN.mm) Dissipation (kN.mm) 8 6 6 6 0.0 4 4 4 0.0 1.0 2.0 3.0 4.0 5.0 2 2 2 Story Drift (%) 0 0 0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Story Drift (%) Story Drift (%) Story Drift (%) (II) Dissipated energy (a) L/d=4 (b) L/d=5 (c) L/d=7 M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ۵

٠٩ / ٠۴ / ١۴٣۶ Replaceable shear link concept in MRFs Analysis results • Hybrid Frame (HF) 2500 2500 2500 RBS 2000 RBS 2000 2000 Hybrid Frame 1500 Hybrid Frame 1500 1500 Base Shear (kN) Base Shear (kN) Base Shear (kN) 1000 1000 1000 500 500 500 0 0 0 -500 -500 -500 -1000 -1000 -1000 -1500 -1500 -1500 -2000 -2000 -2000 -2500 -2500 -2500 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0 Story Drift (%) Story Drift (%) Story Drift (%) (I) Load-displacment curves 14 12 12 x 100000 x 100000 x 100000 12 RBS RBS RBS 10 10 Hybrid Frame Hybrid Frame 10 Hybrid Frame 8 8 Accumulative Energy Link Accumulative Energy Accumulative Energy Dissipation (kN.mm) Dissipation (kN.mm) Link Dissipation (kN.mm) Link 8 Beam 6 Beam 6 Beam 6 4 4 4 2 2 2 0 0 0 0.0 1.0 2.0 3.0 4.0 5.0 0.0 1.0 2.0 3.0 4.0 5.0 0.0 1.0 2.0 3.0 4.0 5.0 Story Drift (%) Story Drift (%) Story Drift (%) (II) Cumulative dissipated energy (a) L/d=4 (b) L/d=5 (c) L/d=7 M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Slit and perforated links Model Perf 1 Perf 2 Perf 3 Perf 4 name D/S 0.24 0.34 0.39 0.6 V y (MPa) 316 291 278 221 Model SL 1 SL 2 SL 3 SL 4 l 0 name b (mm) 28.13 27.73 27.50 27.72 l 0 (mm) 36.54 39.06 40.44 51.34 b V y (MPa) 316 291 278 221 M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ۶

٠٩ / ٠۴ / ١۴٣۶ Slit and perforated links • Damage Index (DI) Model ���� ��� � (Chao, Khandelwal et al. (2006)) exp �1.5max ��� PEEQ = equivalent plastic strain, T = triaxiality � ratio of hydrostatic stress to Mises stress) M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Slit and perforated links Verification of model 35 0.084 rad (DI = 1.51) DI = 1.3 25 Link Shear: V (kN) 15 5 -5 -15 test -25 Pre-DI=1.0 DI = 1.0 Post-DI=1.0 -35 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Link Rotation: γ (rad) DI exceeding 1 at the cycle with maximum rotation of 0.07 rad (10cm) Damage Index 1.510 1.384 1.259 1.133 1.007 0.881 0.755 0.629 0.503 0.378 0.252 0.126 0.000 (picture by courtesy of F. Albermani) M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ٧

٠٩ / ٠۴ / ١۴٣۶ Slit and perforated links Verification of model 800 0.12 rad 600 DI = 1.3 Damage Index Link Shear: V (kN) 400 1.004 0.920 200 0.837 0.753 0.669 0 0.586 0.502 -200 0.418 0.335 0.251 -400 0.167 0.084 0.000 -600 Test Pre-DI=1.0 DI = 1.0 -800 Post-DI=1.0 -0.15 -0.1 -0.05 0 0.05 0.1 0.15 Inelastic Rotation: γ (rad) DI exceeding 1 at the cycle with maximum inelastic rotation of 0.09 rad Damage Index 1.589 1.457 1.324 1.192 1.060 0.927 0.795 0.662 0.530 0.397 0.265 0.132 0.000 (picture by courtesy of T. Okazaki) DI at the point of test failure (inelastic rotation = 0.12 rad) M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES Slit and perforated links Results • Link over-strength comparison Vy/Vy s = 0.83 Vy/Vy s = 0.76 Vy/Vy s = 0.73 Vy/Vy s = 0.58 Rotation Perf1 SL1 Ra Ratio Perf2 SL2 Ra Ratio Perf3 SL3 Ratio Ra Perf4 SL4 Ra Ratio 0.006 0.061 0.102 0.008 0.061 0.129 0.009 0.082 0.115 0.007 0.075 0.093 0.006 006 0.015 015 0.022 0.167 0.129 0.028 0.171 0.163 0.029 0.230 0.127 0.023 0.241 0.095 0.080 0.621 0.128 0.098 0.638 0.153 0.107 0.850 0.126 0.090 0.895 0.100 0.046 046 0.080 080 0.165 1.020 0.161 0.190 1.043 0.182 0.204 1.357 0.150 0.177 1.496 0.118 0.299 1.404 0.213 0.331 1.413 0.234 0.359 1.830 0.196 0.401 2.018 0.199 0.129 129 Why???? Why so low in perf? M. T. Nikoukalam FE INVESTIGATION OF A NEW STRUCTURAL SHEAR FUSES IN MOMENT RESISTING FRAMES ٨