nees grand challenge project opensees user workshop ...sokocalo.engr.ucdavis.edu/~jeremic/ · nees...

NEES Grand Challenge Project

OpenSees User Workshop

Geotechnical tools

Boris Jeremic

Department of Civil and Environmental Engineering

University of California, Davis

Jeremic, Jan 2004 1

Motivation

• Create high fidelity models of constructed facilities (bridges, build-

ings, port structures, dams...).

• Models will live concurrently with the physical system they repre-

sent.

• Models to provide owners and operators with the capabilities to

assess operations and future performance.

• Use observed performance to update and validate models through

simulations.

Jeremic, Jan 2004 2

Goal

• Develop and use computational models in order to

– Design physical tests

– Use observed behavior to validate and improve models

– Use validated models to predict behavior of realistic bridge

systems

• Educate users about new, exciting simulation tools that are now

available

Jeremic, Jan 2004 3

Presentation Overview

• Validating computational models

• Enabling Technologies

– Template Elasto–Plasticity– Full Coupling of Solid and Fluid– Domain Reduction Method– Distributed Memory Parallel Computing– General Large Deformations

• Geomechanics Applications

– Constitutive behavior of test specimens– Behavior of piles in layered soils– Interactions of piles in pile groups– Wave propagation in saturated soils– Seismic behavior of soils and soil-structure interactions

Jeremic, Jan 2004 4

Goals of Validation

Quantification of uncertainties and errors in the computational

model and the experimental measurements

• Goals on validation

– Tactical goal: Identification and minimization of uncertainties

and errors in the computational model

– Strategic goal: Increase confidence in the quantitative predictive

capability of the computational model

• Strategy is to reduce as much as possible the following:

– Computational model uncertainties and errors

– Random (precision) errors and bias (systematic) errors in the

experiments

– Incomplete physical characterization of the experiment

Jeremic, Jan 2004 5

Validation Experiments

• A validation experiment should be jointly designed and executed

by experimentalist and computationalist

– Need for close working relationship from inception to documen-

tation

– Elimination of typical competition between each

– Complete honesty concerning strengths and weaknesses of both

experimental and computational simulations

• A validation Experiment should be designed to capture the relevant

physics

– Measure all important modeling data in the experiment

– Characteristics and imperfections of the experimental facility

should be included in the model

Jeremic, Jan 2004 6

Application Domain

DomainApplication

System Parameter

Sys

tem

com

plex

ity

System Parameter

Sys

tem

com

plex

ity

System Parameter

Sys

tem

com

plex

ity

DomainValidation

DomainApplication

DomainValidation

ApplicationDomain

DomainValidation

Inference

Complete Overlap Partial Overlap No Overlap

• Inference ⇒ Based on physics or statistics

• Validation domain is actually an aggregation of tests (points) and

might not be convex (bifurcation of behavior)

• NEES research provides for validation domain (experimental facil-

ities) that are mostly (if not exclusively) non–overlapping with

the application domain.

Jeremic, Jan 2004 7

Enabling Technologies

• Basic formulation to establish application domain (will skip theory

this time)

• Follow on–line notes for my course: Computational Geomechanics

• Papers and reports available on–line as well

• Simple examples of unit element numerical tests

Jeremic, Jan 2004 8

The Simulations ToolGeotechnical Part

• Fairly strictly based on Thermodynamics (Geomechanics)

• Small deformation, single phase, linear and nonlinear elasticity and

incremental elasto–plasticity (including 1D PY springs, 2D and 3D

solids)

• General, large deformation huperelasticity and hyperelasto–

plasticity

• Full coupling of solid and fluid (u − p − U), (small deformations

only at the moment

• Seismic input through the Plastic Bowl Method (aka Domain

Reduction Method), allows spatial variation in motions...)

• Visualization tools (post–processing)

Jeremic, Jan 2004 9

Analysis Phases

Next load stage

Finish

Next load increment

Loading Stage

Load Increments

Equilibrium Iterations

No equilibrium yet

Self weigth, construction stages,excavations...

Path dependent materials, mimic physics, static of dynamic

Explicit (single step), Iterations (equilibrium within tolerance)

Jeremic, Jan 2004 10

Equilibrium Iterations

• Local, constitutive level iterations

• Global, finite element level iterations

• Convergence criteria

• Convergence tolerance

• Newton family of methods


Template Elasto–Plasticity

Yield function (or lack of YF), potential function (and/or flow

directions), hardening/softening laws (scalar, rotational/translational

kinematic, distortional...)

• Independent definitions of:

1. Yield function (and it’s derivatives)

2. Plastic flow direction (first and second derivatives of potential

function)

3. Evolutions laws for the above two

• This is used to create Template Elastic–Plastic Models


Template Commands

#Elastic-plastic Drucker-Prager model with von Mises Plastic Potential# Yield surfaceset YS "-DP"# Potential surfaceset PS "-VM"# Scalar evolution law: linear hardening coef = 1.0set ES1 "-Leq 1.0"# Tensorial evolution law: linear hardening coef. = 0.0set ET1 "-Linear 0.0"# initial stressset stressp "0.10 0 0 0 0.10 0 0 0 0.10"#__________E________Eo____v___rho______________alpha___kset EPS "70000.0 70000.0 0.2 1.8 -NOD 1 -NOS 2 0.2 0.0 -stressp $stressp"# where alpha=2*sin(phi)/(3^0.5)/(3-sin(phi)), phi->friction angle, k->cohesion

# Put together all the components in a working elastic-plastic material modelnDMaterial Template3Dep 1 -YS $YS -PS $PS -EPS $EPS -ELS1 $ES1 -ELT1 $ET1#brick element tag 8 nodes matID bforce1 bforce2 bforce3 rhoelement brick 1 5 6 7 8 1 2 3 4 1 0.0 0.0 -9.81 1.8


Template Elastic–Plastic Models

• Yield surfaces: von Mises VM, Drucker–Prager DP, Rounded Mohr–

Coulomb RMC, Cam–Clay CC, Parabolic Leon PL (still in testing),

• Plastic flow directions (potential surfaces): von Mises VM, Drucker–

Prager DP, Rounded Mohr–Coulomb RMC, Cam–Clay CC, Manzari–

Dafalias (bounding surface plasticity) MD, Parabolic Leon PL (still

in testing),


Template Elastic–Plastic Models(contd)

• Isotropic or kinematic hardening/softening

– linear and/or nonlinear isotropic hardening/softening of up to 4

scalar internal variables

– linear or nonlinear kinematic hardening/softening of up to 4

tensorial internal variables

∗ Armstrong–Fredericks nonlinear kinematic hardening/softening

of up to 4 tensorial internal variables

∗ Bounding surface nonlinear (Dafalias–Popov) kinematic hard-

ening/softening of up to 4 tensorial internal variables

• Hierarchical database of models (by materials)


3D Solid Elements

Three types of brick elements:

• 8 node brick element Brick8N#_______________tag_____8 nodes_____matID__bforce1_bforce2_bforce3_rho

element Brick8N 1 1 2 3 4 5 6 7 8 1 0.0 0.0 $g $rho

• 20 node brick element Brick20N

• 27 node brick element Brick27N


Examples

• Pure_Shear_Test.ops

• Triaxial_Test.ops

• Simple_Shear_Test.ops


Template Examples

0 2 4 6 8 100

5

10

15

20

25

30

35

40

εa (%)

q (k

Pa)

0 2 4 6 8 10−7

−6

−5

−4

−3

−2

−1

0

1

εa (%)

ε v (%

)0 2 4 6 8 10

0

5

10

15

20

25

30

εa (%)

q (k

Pa)

0 2 4 6 8 100

0.1

0.2

0.3

0.4

0.5

εa (%)

ε v (%

)

0 2 4 6 8 100

5

10

15

20

25

30

εa (%)

q (k

Pa)

0 2 4 6 8 100

0.5

1

1.5

2

2.5

3

3.5

εa (%)

ε v (%

)

0 2 4 6 8 100

5

10

15

20

25

30

35

40

εa (%)

q (k

Pa)

0 2 4 6 8 10−1

−0.5

0

0.5

εa (%)

ε v (%

)

0 2 4 6 8 100

50

100

150

200

εa (%)

q (k

Pa)

0 2 4 6 8 100

0.5

1

1.5

2

2.5

3

εa (%)

ε v (%

)

0 5 10 150

10

20

30

40

50

60

εa (%)

q (k

Pa)

0 5 10 15−12

−10

−8

−6

−4

−2

0

2

εa (%)

ε v (%

)


Template Cyclic Examples

−0.4 −0.2 0 0.2 0.4−10

−5

0

5

10

15

εa (%)

q (k

Pa)

−0.4 −0.2 0 0.2 0.40

0.1

0.2

0.3

0.4

0.5

0.6

0.7

εa (%)

ε v (%

)

−0.4 −0.2 0 0.2 0.4−10

−5

0

5

10

εa (%)

q (k

Pa)

−0.4 −0.2 0 0.2 0.4−0.15

−0.1

−0.05

0

0.05

0.1

0.15

0.2

0.25

εa (%)

ε v (%

)

−0.15 −0.1 −0.05 0 0.05 0.1 0.15−20

−10

0

10

20

30

εa (%)

q (k

Pa)

−0.1 −0.05 0 0.05 0.1 0.15−0.5

0

0.5

1

1.5

2

2.5

3

εa (%)

ε v (%

)


Winkler Spings (aka PY springs)

• uniaxialMaterial PySimple1 matTag? soilType? pult? y50? Cd? <c>

• uniaxialMaterial TzSimple1 matTag? tzType? tult? z50? <c>

• uniaxialMaterial QzSimple1 matTag? qzType? qult? z50? <suction? c?>

• uniaxialMaterial PySimple1 1 1 100 0.01 0.0

• element zeroLength 2 2 3 -mat 1 -dir 1

• Type is usually set to 1 for clay and 2 for sand.

• Note that p and pult p are distributed loads [force per length

of pile] in common design equations, but are both loads for this

uniaxialMaterial [i.e., distributed load times the tributary length of

the pile].


Full Coupling of Solid and Fluid

• General form, full coupling, (currently only small deformations)

• DOFs: uLj → solid displacement pL → fluid pressure ULj → fluid

displacement

• 8 node brick element Brick8N_u_p_U#(28 args)____________tag____8 nodes____matID_bforce1_bforce2_bforce3

porosity alpha solid_density fluid_density

perm_x perm_y perm_z s_bulk_modu f_bulk_modu pressure

element Brick8N_u_p_U 1 5 6 7 8 1 2 3 4 1 0.0 0.0 -9.81

0.8 1.0 1.8 1.0

10e-5 10e-5 10e-5 10e5 10e5 0

• 20 node brick element Brick20N_u_p_U


Plastic Bowl Loading(aka Domain Reduction Method)

• Based on work by Bielak et al. at CMU.

• Seismic motions and accelerations input at the layer of elements

that encompass an elastic–plastic zone (using SHAKE, Green’s

functions, Quake, SCEC...), non–reflective boundaries• pattern PBowlLoading 1 -pbele "$Dir/PBElements.dat"

-acce "$Dir/Inp_acce.dat" -disp "$Dir/Inp_disp.dat" -dt 0.02-factor 1 -xp 6.0 -xm -6.0 -yp 6.0 -ym -6.0 -zp 0.0 -zm -17.5

Fault

Plastic (Soil) "Bowls"


General Large DeformationsHyperelasto–Plasticity

• In implementation phase (issues with material models defined in

terms of various stress measures (first and second Piola–Kirchhoff,

Mandel, Kirchhoff, Cauchy)

0 2 4 6 8 100

2

4

6

8

10

12

14x 10

6

shear strain γ

σ 13 [P

a]

Neo−HookeanLogarithmicMooney−RivlinOgden

0 0.5 1 1.5 2 2.50

0.5

1

1.5

2

2.5

3x 10

6

Tensive strain γ

σ 33 [P

a]

Neo−HookeanLogarithmicOgden−SimoMooney−Rivlin−Simo


Distributed MemoryParallel Computing

• Distributed memory parallel (DMP) computational model.

• Portable from Beowulf clusters (local networks, bootable CDs) to

commercial parallel machines.


Pre– and Post–Processing

• Many small packages around, available for UNIX–like (including

Apple) and/or MS Windows systems.

• Work on pre and post processing packages that are problem specific

• Use Matlab, Mathematica, GNUplot, Excell for simple post-

processing


Joey3D


Phantom


Geotechnical Applications

• Constitutive behavior of test specimens

• Behavior of piles in layered soils

• Interactions of piles in pile groups

• Wave propagation in saturated soils

• Seismic behavior of soils and soil-structure interactions


Long Specimen

Progression of plastic zone for a long specimen with high friction

end platens


Non–Level End Platens


Constitutive Response?

0 0.5 1 1.5 2 2.5 30

50

100

150

200

250

300

350

Shear Strain ε (%)

q (k

Pa)

Without Friction − Cubic Sample With Friction − Cubic SampleWithout Friction − 2 to 1 Sample With Friction − 2 to 1 Sample

0 0.5 1 1.5 2 2.5 3 3.534

34.5

35

35.5

36

36.5

37

37.5

38

Max. inclination angle (deg)

Mob

ilize

d fr

ition

ang

le a

t 2.0

% a

xial

str

ain

Actual friction angle: 37.0o


Single Pile in Layered Soils

−1000 0 1000 2000−10

−8

−6

−4

−2

0

2

SAND

φ = 37.1o

−1.718

SOFT CLAY

Cu = 21.7 kPa

−3.436

SAND

φ = 37.1o

Bending Moment (kN.m)

Dep

th (

m)

SAND

φ = 37.1o

−1.718

SOFT CLAY

Cu = 21.7 kPa

−3.436

SAND

φ = 37.1o

SAND

φ = 37.1o

−1.718

SOFT CLAY

Cu = 21.7 kPa

−3.436

SAND

φ = 37.1o

−400 −200 0 200 400 600−10

−8

−6

−4

−2

0

2

Shear Force (kN)−100 0 100 200 300

−10

−8

−6

−4

−2

0

2

Lateral Resistance (kN/m)−1000 0 1000 2000

−10

−8

−6

−4

−2

0

2

SAND

φ = 37.1o

−1.718

SOFT CLAY

Cu = 21.7 kPa

−3.436

SAND

φ = 37.1o

Bending Moment (kN.m)

Dep

th (

m)

−400 −200 0 200 400 600−10

−8

−6

−4

−2

0

2

Shear Force (kN)−100 0 100 200 300

−10

−8

−6

−4

−2

0

2

Lateral Resistance (kN/m)


p− y Response for Single Pile inLayered Soils

0 2 4 6 8 10 120

50

100

150

200

250

300

Lateral Displacement y (cm)

Late

ral P

ress

ure

p (k

N/m

)

Depth −0.322Depth −0.537Depth −0.752Depth −0.966Depth −1.181Depth −1.396Depth −1.611Depth −1.825Depth −2.040Depth −2.255Depth −2.470Depth −2.684

0 2 4 6 8 10 120

50

100

150

200

250

300

Lateral Displacement y (cm)La

tera

l Pre

ssur

e p

(kN

/m)

Depth −0.322Depth −0.537Depth −0.752Depth −0.966Depth −1.181Depth −1.396Depth −1.611Depth −1.825Depth −2.040Depth −2.255Depth −2.470Depth −2.684

• Influence of soft layers propagates to stiff layers and vice versa

• Can have significant effects in soils with many layers


Examples

• Series of files in SPtcl and SinglePileModel directory

• Single pile (elastic, solid beam or beam-column) in soil (solids)

• Stages of loading (self weight of soil only, static pushover)


Pile Group Simulations

• 4x3 pile group model and plastic zones


Out of Plane Effects

• Out-of-loading-plane bending moment diagram,

• Out-of-loading-plane deformation.


Load Distribution per Pile

0 1 2 3 4 5 6 7 8 9 10 115

6

7

8

9

10

11

12

13

14

15La

tera

l Loa

d D

istr

ibut

ion

in E

ach

Pile

(%

)

Displacement at Pile Group Cap (cm)

Trail Row, Side PileThird Row, Side PileSecond Row, Side PileLead Row, Side PileTrail Row, Middle PileThird Row, Middle PileSecond Row, Middle PileLead Row, Middle Pile


Piles Interaction at -2.0m

• Note the difference in response curves (cannot scale single pile

response for multiple piles)


Validation with Centrifuge Tests

0 1 2 3 4 5 6 7 8 9 1015

20

25

30

35

40

45

Late

ral L

oad

dist

ribut

ion

in e

ach

row

(%

)

Lateral Displacement at Pile Group Cap (cm)

FEM − Trail RowFEM − Third RowFEM − Second RowFEM − Lead RowCentrifuge − Trail RowCentrifuge − Third RowCentrifuge − Second RowCentrifuge − Lead Row


Seismic Wave Propagation Model

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

−27.3

−23.3

−21.8

−18.3

−14.8

−11.8

−8.8

−6.3

−3.3

−1.8

0.0

Time (s)

Acc

eler

atio

n (m

/s2 )

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5−27.3

−23.3

−21.8

−18.3

−14.8

−11.8

−8.8

−6.3

−3.3

−1.8

0.0

Time (s)

Dis

plac

emen

t (m

)


Seismic Wave PropagationSoft Soil

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0.0625−27.3

0.0633−23.3

0.0678−21.8

0.0749−18.3

0.0846−14.8

0.0960−11.8

0.1076 −8.8

0.1160 −6.3

0.1208 −3.3

0.1207 −1.8

0.1181 0.0

Max

Time (s)

Dis

plac

emen

t (m

)

Z

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0.0622−25.0

0.0779−21.0

0.0837−19.5

0.0982−15.0

0.1069−11.0

0.1123 −7.0

0.1169 −4.3

0.1174 −3.6

0.1179 −1.8

0.1181 0.0

0.1183 1.8

0.1178 3.6

0.1173 4.3

0.1129 7.0

0.1075 11.0

0.0984 15.0

0.0837 19.5

0.0779 21.0

0.0622 25.0

Max

Time (s)

Dis

pala

cem

ent (

m)

Y


Seismic Wave PropagationStiff Soil

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0.0625−27.3

0.0658−23.3

0.0724−21.8

0.0735−18.3

0.0745−14.8

0.0753−11.8

0.0758 −8.8

0.0761 −6.3

0.0762 −3.3

0.0762 −1.8

0.0760 0.0

Max

Time (s)

Dis

plac

emen

t (m

)

Z

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

0.0622−25.0

0.0715−21.0

0.0727−19.5

0.0737−15.0

0.0746−11.0

0.0754 −7.0

0.0759 −4.3

0.0759 −3.6

0.0760 −1.8

0.0760 0.0

0.0760 1.8

0.0759 3.6

0.0758 4.3

0.0754 7.0

0.0746 11.0

0.0737 15.0

0.0726 19.5

0.0715 21.0

0.0622 25.0

Max

Time (s)

Dis

plac

emen

t (m

)

Y


SSI Model

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

−38.0

−30.0−28.0

−20.0

−16.0

−12.0

−8.0

−4.0

0.0

Time (s)

Acc

eler

atio

n (m

/s2 )

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5−38.0−30.0

−28.0

−20.0

−16.0

−12.0

−8.0

−4.0

0.0

Time (s)

Dis

plac

emen

t (m

)

Files in directory DRMtcl


SSI Model Free FieldStiff Elastic–Plastic Soil

0 1 2 3 4 5 6 7 8 9 10

0.0000−38.0

0.0052−30.00.1055−28.0

0.1142−20.0

0.1183−16.0

0.1219−12.0

0.1576 −8.0

0.1947 −4.0

0.2002 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max

0 1 2 3 4 5 6 7 8 9 10

0.2002 0.0

0.1937 4.0

0.1749 8.0

0.1261 12.0

0.1231 16.0

0.1139 24.0

0.0124 26.0

0.0000 34.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max


SSI Model Pile–ColumnStiff Elastic–Plastic Soil

0 1 2 3 4 5 6 7 8 9 10

0.0000−38.0

0.0052−30.00.1055−28.0

0.1142−20.0

0.1183−16.0

0.1222−12.0

0.1496 −8.0

0.1899 −4.0

0.2091 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max

0 1 2 3 4 5 6 7 8 9 10

0.2091 0.0

0.1935 4.0

0.1751 8.0

0.1262 12.0

0.1232 16.0

0.1139 24.0

0.0124 26.0

0.0000 34.0

Time (s)

Dis

plac

emen

t (m

)

Y(m) Max


SSI Model Free FieldSoft Elastic–Plastic Soil

0 1 2 3 4 5 6 7 8 9 10

0.0000−38.0

0.0140−30.00.0971−28.0

0.1096−20.0

0.1190−16.0

0.1261−12.0

0.1622 −8.0

0.2823 −4.0

0.3158 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m)

0 1 2 3 4 5 6 7 8 9 10

0.3158 0.0

0.2890 4.0

0.2545 8.0

0.1567 12.0

0.1512 16.0

0.1338 24.0

0.0362 26.0

0.0000 34.0

Time (s)

Dis

plac

emen

t (m

)

Y(m) Max


SSI Model Pile–ColumnSoft Elastic–Plastic Soil

0 1 2 3 4 5 6 7 8 9 10

0.0000−38.0

0.0140−30.00.0976−28.0

0.1094−20.0

0.1207−16.0

0.1227−12.0

0.1328 −8.0

0.2448 −4.0

0.3680 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max

0 1 2 3 4 5 6 7 8 9 10

0.3680 0.0

0.2896 4.0

0.2536

8.0

0.1549

12.0

0.1497

16.0

0.1331

24.0 0.0356

26.0

0.0000 34.0

Time (s)


SSI Model: Pile–Column Behavior

0 1 2 3 4 5 6 7 8 9 10−0.03

−0.02

−0.01

0

0.01

0.02

0.03

0.04

Dis

plac

emnt

(m

)

Time (s)0 1 2 3 4 5 6 7 8 9 10

−0.25

−0.2

−0.15

−0.1

−0.05

0

0.05

0.1

0.15

0.2

0.25

Dis

plac

emen

t (m

)

Time (s)

Stiff soil Soft soil


SSI Model: Seismic Results

0 5 10 15 20 25 30 35 40

0.0000−38.0

0.0077−30.0

0.0783−28.0

0.0791−20.0

0.0844−16.0

0.0878−12.0

0.1248 −8.0

0.1800 −4.0

0.1946 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max

0 5 10 15 20 25 30 35 40

0.0000−38.0

0.0224−30.0

0.0879−28.0

0.1102−20.0

0.1161−16.0

0.1227−12.0

0.3961 −8.0

0.6258 −4.0

0.6928 0.0

Time (s)

Dis

plac

emen

t (m

)

Z(m) Max

Stiff soil Soft soil


Wave Propagation in SaturatedSoils

0 0.05 0.1 0.15 0.2 0.25 0.3−4

−3

−2

−1

0

1

2x 10

−3

Sol

id D

ispl

acem

ent (

m)

Top node2m from top4m from top6m from top

0 0.05 0.1 0.15 0.2 0.25 0.3−0.5

0

0.5

1

Por

e pr

essu

re (

kPa)

0 0.05 0.1 0.15 0.2 0.25 0.3−4

−3

−2

−1

0

1

2x 10

−3

Time (sec)

Flu

id D

ispl

acem

ent (

m)

0 0.05 0.1 0.15 0.2 0.25 0.3−4

−3

−2

−1

0

1

2x 10

−3

Sol

id D

ispl

acem

ent (

m)

Top node2m from top4m from top6m from top

0 0.05 0.1 0.15 0.2 0.25 0.3−0.5

0

0.5

1

Por

e pr

essu

re (

kPa)

0 0.05 0.1 0.15 0.2 0.25 0.3−4

−3

−2

−1

0

1

2x 10

−3

Time (sec)

Flu

id D

ispl

acem

ent (

m)

Half space, ramp load k = 10−3,5m/s


Soil–Structure Interaction


SSI AdvantageousH

oriz

anta

l Dis

plac

emen

t (m

)

0.1

0.05

0

−0.05

−0.1

−0.150 5 10 15 20 25 30 35 40 45 50

Time (Sec)

Fixed Model SFSI Model

She

ar F

orce

(N

)

4

6

2

0

−2

−4

−6

−8

x 10

Fixed ModelSFSI model

−0.15 −0.1 −0.05 0Displacement (m)

0.05 0.1

6

Kobe–JMA


SSI DisadvantageousH

oriz

anta

l Dis

plac

emen

t (m

)

Time (Sec)0 5 10 15 20 25 30 35 40

Fixed Model SFSI Model

0.5

0.4

0.3

0.2

0.1

0

−0.1

−0.2

−0.3

−0.4

−0.5

6

She

ar F

orce

(N

)

−2

0

2

4

6

−4

−6

−8−0.5 −0.4 −0.3 −0.2 −0.1 0 0.1 0.2 0.3 0.4 0.5

Displacement (m)

Fixed ModelSFSI model

x 10

LP–Corralitos


Conclusions

• Examples, lecture notes, executables available at:

http://sokocalo.engr.ucdavis.edu/~jeremicand at

http://opensees.berkeley.edu/

• Manual is constantly being improved

• Executables available for both UNIX-like (up–to–date, preferable)

and MS Windows.

• MS Windows, soon to have up to date executables


nees grand challenge project opensees user workshop ...sokocalo.engr.ucdavis.edu/~jeremic/ · nees...

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