Seismic performance quantification of steel corrugated shear wall system

Transcription

1 Seismic performance quantification of steel corrugated shear wall system Laszlo Gergely Vigh, (Geri) Visiting scholar, Stanford, CA Asst. Prof., Budapest University of Technology and Economics, Dept. Of Structural Engineering, Hungary and Professor Gregory Deierlein, Professor Eduardo Miranda, Abbie Liel (Stanford) Stephen Tipping (Tipping Mar + Associates) Thanks are due to: The Thomas Cholnoky Foundation, Inc.

2 Little background Hard to work at Dept. of Structural Engineering

3 Little background Hard to work at Dept. of Structural Engineering

4 Little background Hard to work at Dept. of Structural Engineering

5 Little background Budapest University of Technology and Economics Source:

6 Little background Budapest University of Technology and Economics

7 Little background Budapest University of Technology and Economics: - 8 faculties and several innovation centers - Faculty of Civil Engineering: 1 departments Dept. of Structural Engineering: staffs: 57 (incl. appr. 25 of asst. prof prof) 22 BSc, 16 MSc courses + optionals

8 Little background Dept. of Structural Engineering 1. Education 2. Research national research funds, and selfish researches 3. Industry & University R&D Co-designer Expert Independent checks Laboratory and site testing Accredited laboratory 4. Student life

9 Seismic performance quantification of steel corrugated shear wall systems

10 Shear wall system corrugated sheet boundary elements screwed connection Tipping Mar and Associates, Berkeley, CA

11 Shear wall system corrugated sheet boundary elements screwed connection

12 Seismic performance quantification by ATC-63 performance quantification by cyclic tests or Applied Technology Council, Project 63 achieves primary life safety performance objective by requiring an acceptably low probability of collapse R, Ω, C d factors 1) idealized archetypical systems: realization, design (assume R) 2) analytical model development and calibration 3) nonlinear static (pushover) analysis Ω 4) nonlinear incremental dynamic analysis (IDA) 5) fragility curves; adjusted collapse margin ratio (ACMR) vs. acceptable ACMR R, C d

13 Experimental results Stojadinovic et al. at UC Berkeley 44 specimens

14 Experimental results pinching hysteresis behavior

15 Experimental results failure modes

16 Experimental results failure modes

17 Shear wall behavior estimation of monotonic backbone curve challenge: - cyclic behavior is path-dependent - calibration to test results we should know the monotonic behavior rigid rigid leaning column nonlin. spring

18 Shear wall behavior estimation of monotonic backbone curve modelling technique ANSYS shell, beam & spring elements

19 Shear wall behavior estimation of monotonic backbone curve single screw connection behavior Source: Dubina et al. literature EC3 published experimental data

20 Shear wall behavior estimation of monotonic backbone curve single screw connection behavior Screw characteristics Force [kn N] elasto-plastic (no hardening) 1 mat. hard. - actual sigma-eps Slip [mm]

21 Shear wall behavior estimation of monotonic backbone curve single screw connection behavior Screw characteristics Force [kn] Slip [mm] 1 with drop no drop 8 no drop, adjusted Load [kn] 6 4 test average envelope adjusted FEM backbone estimated capping point 2 FEM with rigid connection Drift [mm]

22 Shear wall behavior estimation of monotonic backbone curve analysis of tested shear walls

23 Shear wall behavior estimation of monotonic backbone curve extension to longer walls Group #14 - Wall length effect 6 5 all models include nonlinear screw behavior and imperfection Load [kn] test, avg. adjusted FEM 4 ft - eq. orthotropic 8 ft - eq. orthotropic 16 ft - eq. orthotropic Drift [mm]

24 Model calibration OpenSees Ibarra Medina Krawinkler model F u F y 2 Load F y 1 α H = α H2 α H2 Combined mat. Mat. #2 residual Mat. #1 α H1 = δ y 1 δ y 2 δ m Drift, δ 12 8 α C Lo oad [kn] F max β p F max α pδ p γ A γ S 1 8 γ D 6 Drift [mm] δ p Load [kn] Drift [mm] γ K Load [kn] #29 (group #14) #26 (group #8) -6 #18 (group #1) group #14 test avg. -8 group #8 test avg. group #1 test avg. -1 Drift [mm]

25 Model calibration calibration: GA variables: α C, α p, β p, γ A, γ S, γ D, γ K encoding: sequence e.g.: possible values of γ A = [ ] 1xN population size: 2 selection: roulette wheel elitism crossover: simple (4) arithmetic (4) heuristic (4) alleles for γ A : 1..N (i.e. based on the sequence number of the possible values) encoding for a chromosome: [ ] mutation: multi-non-uniform (8)

26 Model calibration final uniform model 1 Spec # Spec # Load [kn] Load [kn] Drift [mm] Drift [mm] 6 4 Spec #44 2 Load [kn] Drift [mm]

27 Model calibration final uniform model 1 Spec # Spec # Load [kn] Load [kn] Drift [mm] Drift [mm] 6 4 Spec #44 2 Load [kn] Drift [mm]

28 Building archetypes Archetype definitions building function, configurations number of stories seismic zone

29 Building archetypes Archetype definitions R = 4 High seismic (SDC Dmax) S S = 1.5, S 1 =.9 (S DS = 1., S D1 =.6) Archetype Story # Function A floor seismic weight Appr. period Upper limit of period S MT (at T a ) C s Design base shear wall length [sqft] [psf] [s] [s] [g] [-] [kip] [ft] 1 1 Commercial Commercial Commercial &2 Family &2 Family Multi-Family Multi-Family Multi-Family

30 Building archetypes seismic design based on assumed R simplified proc: equivalent static loading Story EQ loading demand, V u wall type V nom V ASD V LRFD [kip] [lbs] [plf] (group#) [plf] [plf] [plf] R 625 lbs

31 Analytical model 2D truss structure rigid rigid nonlin. spring leaning column

32 Pushover analysis Base shear force [kn] V max V 8% V 6% V design Ω = 2.57 Archetype #15 V max = 214 kn; V design = 84 kn Ω = 2.57 δ y = 6.7 mm; δ u = mm µ C = 2.72 T =.526 s SSF = 1.2 Archetype #15 V max = 214 kn (roof displ. = 138 mm) 5 Pushover analysis δ y δ design base shear u Roof displacement [mm] (displ. factor x1) 6.1 m

33 IDA analysis each archetype 44 EQ records nonlin. dyn. analysis max. interstory drift a g [g] Drift [mm] 1.5 Ground acceleration Time [s] Floor #1 interstory drift 1 5 Drift [mm] Time [s] Floor #4 interstory drift 5 d [mm] Time [s] Roof displacement Time [s]

34 IDA analysis

35 IDA analysis each archetype each record scaled up to collapse 5 Archetype #15 1 Archetype # S CT [g] S CT,median = 2.93g S MT = 1.5g (at T =.526s) Probability [-] S CT,median = 2.93g CMR = σ x 2 =.96 σ x = Interstory drift [%].1 S MT = 1.5g (at T =.526s) S CT [g] (adjusted) collapse margin ratio

36 IDA analysis or

37 Discussion comparison to wooden shear wall Force, F F K 1 K P 1 r 1 K 1 1 r 2 K F max r 3 K 1 F I r 4 K 1 Displacement, max = β un F = un u (F + r 1 K ) [1 exp(- Load [kn] -4-8 F u + r 2 K ( - u ), αpδp δp βpf max Drift [mm] K P = K [(F /K )/ max ] α

38 Discussion comparison to wooden shear wall M e d i a n S a a t T = 1 9 s e c ( g ) CMR = 2.15/1.5 = 1.43 X 1.43 S CT (T =.26 s) = 2.15 g S MT (T =. 26 s) = 1.5 g Maximum Interstory Drift Ratio (%) S CT [g] Archetype #5 S CT,median = 3.5g S MT = 1.5g (at T =.265s) Interstory drift [%] in general, very similar results

39 Further observations Effect of scaling fundamental period 5 Archetype #19 5 Archetype #19 S CT [g] S CT,median = 2.43g S MT = 1.2g (at T =.749s) Interstory drift [%] S CT [g] S CT,median = 2.93g S MT = 1.5g (at T =.495s) Interstory drift [%] a) scaled at T upper =.749 s b) scaled at T model =.495 s

40 Further observations Effect of scaling fundamental period 5 Archetype #17 5 Archetype #17 S CT [g] S CT,median = 2.45g 2 S MT = 1.49g (at T =.63s) Interstory drift [%] S CT [g] S CT,median = 2.98g 2 S MT = 1.5g (at T =.423s) Interstory drift [%] a) scaled at T upper =.64 s b) scaled at T model =.423 s

41 Further observations Model parameter sensitivity capping displ mm capping slope %.α P.75.4 β P % adjusted initial stiffness +6% 1.4 x strength +3%

42 Performance quantification check R = 4 High seismic (SDC Dmax) S S = 1.5, S 1 =.9 (S DS = 1., S D1 =.6) Archetype Story # Function Ω µ C SSF S MT (T upper ) SF anchor β tot Ŝ CT CMR ACMR [-] [-] [-] [g] [-] [-] [g] [-] [-] 1 1 Commercial > 5 2 Commercial > 9 3 Commercial > Mean 2.45 > 2 1 1&2 Family > 6 2 1&2 Family > 1 3 Multi-Family > 13 4 Multi-Family > 15 5 Multi-Family > Mean 3.3 >

43 Performance quantification even for taller buildings R = 4 High seismic (SDC Dmax) S S = 1.5, S 1 =.9 (S DS = 1., S D1 =.6) Archetype Story # Function Ω µ C SSF S MT (T upper ) SF anchor β tot Ŝ CT [-] [-] [-] [g] [-] [-] [g] 2 1 1&2 Family &2 Family Multi-Family Multi-Family Multi-Family Multi-Family Multi-Family Multi-Family Multi-Family

44 Performance quantification R = 4! results and component behavior are very similar to + wooden shear wall as good as wood R = 6 is in code for wooden shear wall additional finishing, partition walls? - short period bldgs! ASD design strength derivation from test +/- uncertainties in the monotonic backbone estimation

45 Performance quantification conventional R factor vs. ATC-63?

46 Thank you for your attention! But don t go anywhere