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Finley A. Charney, Ph.D. P.E. Francisco Flores, Ph.C.
Advanced Analysis and Modeling Techniques in
Structural Earthquake Engineering
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Syllabus
Lecture Date Topic
1 March 13 Introduction to OpenSEES and TCL
Introduction to OpenSees. Install Tcl and OpenSees.
Modeling a 2 Story frame. Apply gravity loads and lateral loads. Check forces and reactions.
2 March 20 Introduction to OpenSEES and TCL, Continued
Perform Modal Analysis using the 2-Story model developed in first class.
Matlab: Animate modes and create videos of the
animations.
3 March 27 Using Phenemonological Models in OpenSEES
Write a script that performs a cyclic test on a zero length element and check different materials.
Matlab: Use matlab to create an input file for OpenSees and
create a video that tries different material parameters to match a specific cyclic test.
4 April 3 Using Fiber Models in OpenSEES in OpenSEES
Using Fiber Models in OpenSEES
Application: Obtain Moment-Rotation plot using a concrete section with fibers.
5 April 10 Modeling a SMF without panel zones
Modeling a 2Story frame including plastic hinges at beams and columns. Analyze under gravity loads and obtain
periods.
6 April 24 Geometric
Nonlinearities in OpenSEES
Perform Pushover analysis and compare curves including and not including P-Delta effects.
7 TBD* Modeling Inherent Damping in OpenSEES
Perform Free Vibration analysis using model created in previous class.
Matlab: Use matlab to calculate inherent damping from the
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Syllabus
Lecture Date Topic
8 May 8 Ground Motion Selection and Scaling
Use of Spectrum Matching tool and Toolkit scaling module
9 May 15 Incremental Dynamic Analysis
Application: Write script to perform nonlinear dynamic analysis and Incremental dynamic analysis.
10 May 22 Example Application of Chapter 16
Modeling 3D structures in OpenSees and other advanced modeling capabilities
11 May 29 Example Application of Chapter 16, continued
Development of 3D example for Chapter 16 analysis
12 June 5 Example application of Chapter 16, continued
Static pushover and evaluation of torsional response
13 June 12 Example Application of Chapter 16, continued
Dynamic analysis and compliance with acceptance criteria
14 June 19 Example Application of P-695
Learning the ToolKit. Use the 2-story model frame to perform analyses.
15 June 26 Example Application of P-695, continued
Using the ToolKit to perform Pushover, IDA and create scripts to run in parallel.
16 July 3 Example Application of P-695, continued
Example of how to submit files to run IDA analyses using NeesHub. The scripts to run the analyses are given by the ToolKit.
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Introducción
• OpenSees por sus siglas “Open System for Earthquake Engineering Simulation” fue desarrollado por el “Pacific Earthquake Engineering Research Center (PEER)” con el apoyo del “National Science Foundation”. • Este software es utilizado para investigación y simulación de sistemas
geotécnicos y estructurales.
• OpenSees usa Tcl/Tk como lenguaje de programación y se extendió con comandos para OpenSees.
• El modelamiento de estructuras es muy flexible, permite la selección de distintos elementos y materiales en conjunto con diferentes aproximaciones cinemáticas para considerar grandes desplazamientos y efectos P-Delta.
• Tiene distintos procedimientos y algoritmos para dar solución a problemas
Instalación
• Descargar OpenSees y Tcl/Tk.
• Instalar Tcl/Tk: la localización por defecto para instalar este
programa es C:\tcl, es muy importante cambiar esto a "C:\Program
Files\Tcl" durante la instalación. Si al correr OpenSees aparece el
error “Cannot find tcl85.dll” es porque no cambio el lugar donde se
debe instalar Tcl y se debe reinstalar.
• Finalmente ubicar ejecutable de OpenSees (opensees.exe) en el
directorio deseado.
Pasos para realizar análisis en OpenSees:
1. Definir modelo 2. Geometría
3. Definir resultados a grabar (“Recorders”) 4. Análisis 7 Define Model (2D o 3D) Model Geometry Define Recorders Analysis
1. Definir Modelo
1. Definir modelo
Definir si modelo va a ser en 2D o 3D y el número de grados de libertad.
Model Command:
Se usa para definir las dimensiones y el número de grados de libertad del modelo.
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2. Geometría
2. Geometría
En este paso, todos los nodos, elementos, materiales, restricciones y cargas son definidas.
2. Geometría
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node $nodeTag (ndm $coords) <-mass (ndf $massValues)>
Node Command:
Comando utilizado para definir nudos de la estructura. Asigna coordenadas y masas (opcional).
Element Command:
Comando utilizado para construir un elemento: element eleType? arg1? ...
Tipos de Elementos en OpenSees:
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ZERO LENGTH ELEMENTS TRUSS ELEMENTS BEAM-COLUMN ELEMENTS
zeroLength Element Truss Element Elastic Beam Column Element
zeroLengthND Element Corotational Truss Element
Elastic Beam Column Element with Stiffness Modifiers
zeroLengthSection Element Beam With Hinges Element
CoupledZeroLength Element Displacement-Based Beam-Column Element
zeroLengthContact Element Force-Based Beam-Column Element
zeroLengthContactNTS2D
Flexure-Shear Interaction Displacement-Based Beam-Column Element
zeroLengthInterface2D zeroLengthImpact3D
JOINT ELEMENTS LINK ELEMENTS BEARING ELEMENTS
BeamColumnJoint Element Two Node Link Element Elastomeric Bearing Element ElasticTubularJoint Element Flat Slider Bearing Element
Joint2D Element Single Friction Pendulum Bearing Element TFP Bearing
Triple Friction Pendulum MultipleShearSpring Element MultipleNormalSpring Element KikuchiBearing Element
QUADRILATERAL ELEMENTS TRIANGULAR ELEMENTS BRICK ELEMENTS
Quad Element Tri31 Element Standard Brick Element Shell Element Bbar Brick Element ShellNL Twenty Node Brick Element Bbar Plane Strain Quadrilateral Element Twenty Seven Node Brick Element Enhanced Strain Quadrilateral Element SSPbrick Element
SSPquad Element
U-P ELEMENTS MISC CONTACT ELEMENTS
UC San Diego u-p element (saturated soil) ShallowFoundationGen SimpleContact2D Element Four Node Quad u-p Element SurfaceLoad Element SimpleContact3D Element Brick u-p Element BeamContact2D Element bbarQuad u-p Element BeamContact3D Element bbarBrick u-p Element BeamEndContact3D Element Nine Four Node Quad u-p Element zeroLengthImpact3D Twenty Eight Node Brick u-p Element
Twenty Node Brick u-p Element Brick Large Displacement u-p Element SSPquadUP Element
2. Geometría
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SP_Constraints: (Single Point Constraint):
Los comandos para crear este tipo de constraints son: fix, fixX, fixY, fixZ.
MP_Constraints: (Multi Point Constraint):
Comandos usados para este tipo de constraints : equalDOF rigidDiaphragm, rigidLink.
Pattern Command:
3. Recorders
13 3. Recorders:
element eleType? arg1? ...
Node
Node Recorder
Node Envelope Recorder Drift Recorder Element/Section/Fiber Element Recorder ElementEnvelopeRecorder Graphics Plot Recorder
4. Análisis
14 4. Análisis:
En este paso, los métodos a usar para analizar la estructura son definidos. En OpenSees, un análisis esta compuesto por diferentes partes o componentes definidas por el usuario. Los componentes a definir previo a todo análisis son:
4. Análisis
15 1. ConstraintHandler:
Determina como las ecuaciones de los “constraints” definidos son realizados en el análisis. Maneja las condiciones de borde o desplazamientos impuestos. a) Plain Constraints: Usado comúnmente con comandos tales como (fix
command) o (equalDOF command). b) Lagrange Multipliers
c) Penalty Method
d) Transformation Method
4. Análisis
16 2. DOF_Numberer:
Determina la manera en que los grados de libertad son numerados para
resolver las ecuaciones. Se los puede renumerar para optimizar la matriz de rigidez y hacer más rápido el análisis.
a) Plain Numberer
b) Reverse Cuthill-McKee Numberer
c) Alternative_Minimum_Degree Numberer
4. Análisis
17 3. SystemOfEqn/Solver:
Especifica como guardar y resolver el sistema de ecuaciones en el análisis. a) BandGeneral SOE b) BandSPD SOE c) ProfileSPD SOE d) SuperLU SOE e) UmfPack SOE f) FullGeneral
g) SparseSYM SOE
h) Mumps
4. Análisis
18 4. Convergence Test:
Determina el método para verificar la convergencia del sistema. a) Norm Unbalance Test
b) Norm Displacement Increment Test c) Energy Increment Test
d) Relative Norm Unbalance Test
e) Relative Norm Displacement Increment Test
f) Total Relative Norm Displacement Increment Test g) Relative Energy Increment Test
h) Fixed Number of Iterations
4. Análisis
19 5) SolutionAlgorithm:
Determina la secuencia de pasos a tomar para resolver las ecuaciones no-lineales en el tiempo presente (t).
a) Linear Algorithm b) Newton Algorithm
c) Newton with Line Search Algorithm d) Modified Newton Algorithm
e) Krylov-Newton Algorithm
f) Secant Newton Algorithm
g) BFGS Algorithm
4. Análisis
20 6. Integrator: determina el paso a predecir para el tiempo t+dt.
Static Integrators:
a) Load Control
b) Displacement Control
c) Minimum Unbalanced Displacement Norm d) Arc-Length Control
Transient Integrators:
a) Central Difference b) Newmark Method
c) Hilber-Hughes-Taylor Method d) Generalized Alpha Method e) TRBDF2
4. Análisis
21 7. Analysis:
Define el tipo de análisis a ser ejecutado.
analysisType
Static - for static analysis
Transient - for transient analysis with constant time step
VariableTransient - for transient analysis with variable time step
