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<!-- INTRODUCTION --> | |||
<h1>Introduction</h1> | |||
The examples in this manual are listed in order of simplicity. | |||
NOTE: gravity analysis is always included as part of the model building | |||
<!-- MODELS --> | |||
<h1>Models</h1> | |||
The following types of models are represented in these examples: | |||
:;<h2>Elastic Elements</h2> | |||
: OpenSees [[Elastic Beam Column Element]] | |||
: The elastic, uncoupled, axial and flexural stiffnesses are defined at the element level | |||
: user specifies: E,I,A | |||
:;<h2>Inelastic Elements</h2> | |||
: OpenSees [[Force-Based Beam-Column Element]] | |||
: Two types of sections | |||
::<h3>Uniaxial Section</h3> | |||
::: The inelastic, uncoupled, axial and flexural stiffnesses are defined at the section level | |||
::: The OpenSees [[Uniaxial Section]] Command is used | |||
::: User specifies: | |||
:::: Axial stiffness A | |||
:::: Section Moment-Curvature characteristics via the OpenSees [[UniaxialMaterial Command]] | |||
::<h3>Fiber Section</h3> | |||
::: The section is broken down into fibers where uniaxial materials are defined independently. | |||
::: The program calculates the coupled flexural and axial stiffnesses/strength by integrating strains across the section | |||
::: The OpenSees [[Fiber Section]] Command is used | |||
::: User specifies | |||
:::: Stress-Strain characteristics via the OpenSees [[UniaxialMaterial Command]] for all number of materials | |||
:::: Section geometry via series of Patches and Layers in the fiber section | |||
::: Two Section Geometries are presented | |||
:::: *RC Rectangular Section | |||
:::: *Standard AISC W section | |||
<!-- LATERAL LOADS --> | |||
<h1>Lateral Loads</h1> | |||
The following types of lateral loads are represented in these examples: | |||
[[File:StaticPushoverLoads_Figure1.GIF|link=OpenSees Examples Manual -- Structural Models & Analyses|right]] | |||
:;<h2> Static Pushover</h2> | |||
: Control node is located at the highest floor | |||
: Lateral-load distribution is proportional the the mass distribution along the height of the building | |||
: Static analysis | |||
: Two types | |||
::<h3>Monotonic Pushover</h3> | |||
::: One-directional displacement-controlled static lateral loading | |||
::<h3>Reversed Cyclic Pushover</h3> | |||
::: One-directional displacement-controlled static lateral loading | |||
::: Displacement cycles are imposed in positive and negative direction | |||
[[File:TimeDependent_Figure1.GIF|link=OpenSees Examples Manual -- Structural Models & Analyses|right]] | |||
:;<h2> Time-Dependent Dynamic Loads</h2> | |||
: Transient analysis | |||
: Four types | |||
::<h3>Uniform Sine-Wave</h3> | |||
::: Sine-wave acceleration input | |||
::: Same acceleration input at all nodes restrained in specified direction | |||
::<h3>Multiple-Support Sine-Wave</h3> | |||
::: Sine-wave displacement input | |||
::: Different displacements are specified at particular nodes in specified directions | |||
::<h3>Uniform Earthquake</h3> | |||
::: Earthquake (from file) acceleration input | |||
::: Same acceleration input at all nodes restrained in specified direction | |||
::<h3>Multiple-Support Earthquake</h3> | |||
::: Earthquake (from file) displacement input | |||
::: Different displacements are specified at particular nodes in specified direction | |||
::<h3>Bidirectional Earthquake</h3> | |||
::: Different inputs are specified for two directions | |||
::: Same acceleration input at all nodes restrained in specified direction | |||
<!-- SIMULATION --> | |||
<h1>Simulation Process</h1> | |||
Each example script does the following:<br> | |||
:<h2>Build the model</h2> | |||
:#model dimensions and degrees-of-freedom | |||
:#nodal coordinates | |||
:#nodal constraints -- boundary conditions | |||
:#nodal masses | |||
:#elements and element connectivity | |||
:#recorders for output | |||
:<h2>Define & apply gravity load</h2> | |||
:#nodal or element load | |||
:#static-analysis parameters (tolerances & load increments) | |||
:#analyze | |||
:#hold gravity loads constant | |||
:#reset time to zero | |||
:<h2> Define and apply lateral load </h2> | |||
:#load pattern (nodal loads for static analysis, support ground motion for earthquake) | |||
:#lateral-analysis parameters (tolerances & displacement/time increments) | |||
:#*Static Lateral-Load Analysis | |||
:#**define the displacement increments and displacement path | |||
:#*Dynamic Lateral-Load Analysis | |||
:#**define the input motion and all associated parameters, such as scaling and input type | |||
:#**define analysis duration and time increment | |||
:#**define damping | |||
:#analyze | |||
The | <h1>Introductory Examples</h1> | ||
The objective of Example 1a and Example 1b is to give an overview of input-file format in OpenSees using simple scripts. <br> | |||
These scripts do not take advantage of the Tcl scripting capabilities shown in the later examples. However, they do provide starting a place where the input file is similar to that of more familiar Finite-Element Analysis software. Subsequent examples should be used as the basis for user input files. | |||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 1a. 2D Elastic Cantilever Column ]]</h2> | |||
<!-- subSECTION 1 --> | <!-- subSECTION 1 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | |- | ||
| style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;"| | |||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example1a_Figure1.gif]] | [[File:Example1a_Figure1.gif|link=OpenSees Example 1a. 2D Elastic Cantilever Column]] | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top;background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*overview of basic OpenSees input structure | *overview of basic OpenSees input structure | ||
*coordinates, boundary conditions, element connectivity, nodal masses, nodal loads, etc. | *coordinates, boundary conditions, element connectivity, nodal masses, nodal loads, etc. | ||
Line 48: | Line 129: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*elastic elements | *elastic elements | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
</div> | </div> | ||
|} | |} | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 1b. Elastic Portal Frame]]</h2> | |||
<!-- subSECTION 2 --> | |||
< | |||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
</div> | [[File:Example1b_Figure1.gif|link=OpenSees Example 1b. Elastic Portal Frame]]</div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*two element types | *two element types | ||
*distributed element loads | *distributed element loads | ||
Line 99: | Line 173: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*elastic elements | *elastic elements | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
Line 118: | Line 192: | ||
|} | |} | ||
|} | |} | ||
<h1>Simple Examples of Nonlinear-Models</h1> | |||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 2a. Elastic Cantilever Column with variables]]</h2> | |||
<!-- subSECTION 1 --> | <!-- subSECTION 1 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example2a_figure1.GIF|link=OpenSees Example 2a. Elastic Cantilever Column with variables]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*introduce variable: define & use | *introduce variable: define & use | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*elastic element | *elastic element | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
Line 168: | Line 241: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 2b. Nonlinear Cantilever Column: Uniaxial Inelastic Section]]</h2> | |||
<!-- subSECTION 2 --> | <!-- subSECTION 2 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example2b_figure1.GIF|link=OpenSees Example 2b. Nonlinear Cantilever Column: Uniaxial Inelastic Section]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*first example of nonlinear model, set nonlinearity at section level | *first example of nonlinear model, set nonlinearity at section level | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*nonlinearBeamColumn element | *nonlinearBeamColumn element | ||
*uniaxial section | *uniaxial section | ||
Line 206: | Line 274: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
Line 217: | Line 285: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 2c. Nonlinear Cantilever Column: Inelastic Uniaxial Materials in Fiber Section ]]</h2> | |||
<!-- subSECTION 3 --> | <!-- subSECTION 3 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example2c_figure1.GIF|link=OpenSees Example 2c. Nonlinear Cantilever Column: Inelastic Uniaxial Materials in Fiber Section ]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*set nonlinearity at material level | *set nonlinearity at material level | ||
*material stress-strain response is assembled into fiber section | *material stress-strain response is assembled into fiber section | ||
Line 247: | Line 310: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*nonlinearBeamColumn element | *nonlinearBeamColumn element | ||
*uniaxial material | *uniaxial material | ||
Line 258: | Line 321: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
Line 268: | Line 331: | ||
|} | |} | ||
|} | |} | ||
<h1>2D Structural Modeling & Analysis Examples</h1> | |||
These examples take advantage of the Tcl scripting language starting from simple variable substitutions in the initial examples, to the more advanced techniques of array management and logical expressions (if-then statements). <br> | |||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 3. Cantilever Column with units]]</h2> | |||
<!-- subSECTION 1 --> | <!-- subSECTION 1 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example3_figure1.GIF|link=OpenSees Example 3. Cantilever Column with unit]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*units, defined and used (they will be used in all subsequent examples) | *units, defined and used (they will be used in all subsequent examples) | ||
*separate model-building and analysis files | *separate model-building and analysis files | ||
Line 300: | Line 362: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*elastic elements | *elastic elements | ||
*inelastic uniaxial section | *inelastic uniaxial section | ||
Line 312: | Line 374: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static pushover | *static pushover | ||
*dynamic earthquake-input | *dynamic earthquake-input | ||
Line 323: | Line 385: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 4. Portal Frame]]</h2> | |||
<!-- subSECTION 2 --> | <!-- subSECTION 2 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example4_figure1.GIF|link=OpenSees Example 4. Portal Frame]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*use previously-defined procedures to simplify input | *use previously-defined procedures to simplify input | ||
*introduce more analysis types | *introduce more analysis types | ||
Line 353: | Line 410: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*elastic elements | *elastic elements | ||
*inelastic uniaxial section | *inelastic uniaxial section | ||
Line 364: | Line 421: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static reversed cyclic analysis | *static reversed cyclic analysis | ||
*dynamic sine-wave input analysis (uniform excitation) | *dynamic sine-wave input analysis (uniform excitation) | ||
Line 379: | Line 436: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 5. 2D Frame, 3-story 3-bay, Reinforced-Concrete Section & Steel W-Section]]</h2> | |||
<!-- subSECTION 3 --> | <!-- subSECTION 3 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example5_figure1.GIF|link=OpenSees Example 5. 2D Frame, 3-story 3-bay, Reinforced-Concrete Section & Steel W-Section]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*2D frame of fixed geometry: 3-story, 3-bay | *2D frame of fixed geometry: 3-story, 3-bay | ||
*nodes and elements are defined manually, one by one | *nodes and elements are defined manually, one by one | ||
Line 408: | Line 460: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*Reinforced-Concrete Section | *Reinforced-Concrete Section | ||
*Steel W-Section | *Steel W-Section | ||
Line 421: | Line 473: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static reversed cyclic analysis | *static reversed cyclic analysis | ||
*dynamic sine-wave input analysis (uniform excitation) | *dynamic sine-wave input analysis (uniform excitation) | ||
Line 436: | Line 488: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 6. generic 2D Frame, N-story N-bay, Reinforced-Concrete Section & Steel W-Section]]</h2> | |||
<!-- subSECTION 4 --> | <!-- subSECTION 4 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example6_figure1.GIF|link=OpenSees Example 6. generic 2D Frame, N-story N-bay, Reinforced-Concrete Section & Steel W-Section]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*2D frame geometry of variable geometry ( # stories and # bays are variables) | *2D frame geometry of variable geometry ( # stories and # bays are variables) | ||
*node and element definition is automated | *node and element definition is automated | ||
Line 466: | Line 513: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*Reinforced-Concrete Section | *Reinforced-Concrete Section | ||
*Steel W-Section | *Steel W-Section | ||
Line 479: | Line 526: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static reversed cyclic analysis | *static reversed cyclic analysis | ||
*dynamic sine-wave input analysis (uniform excitation) | *dynamic sine-wave input analysis (uniform excitation) | ||
Line 493: | Line 540: | ||
|} | |} | ||
|} | |} | ||
<h1>3D Structural Modeling & Analysis Examples</h1> | |||
<blockquote> | |||
A few items are new in 3D: | |||
*Additional coordinates need to be considered in defining nodes | |||
*Additional degrees of freedom need to be considered in defining the following: | |||
**nodal constraints (boundary conditions) | |||
**nodal masses | |||
**nodal loads | |||
*The transformation from local element/section coordinates to global system coordinates needs to be specified | |||
*Element loads are specified in local coordinates | |||
*Additional arguments are required for many elements (bending about local-y axis) properties | |||
*Element/Section torsional stiffness needs to be considered | |||
*Rigid floor diaphragms need be included for building models | |||
</blockquote> | |||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 7. 3D Frame, 3-story 3-bayX 3-bayZ, Reinforced-Concrete Section & Steel W-Section]]</h2> | |||
< | |||
<!-- subSECTION 1 --> | <!-- subSECTION 1 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example7_figure1.GIF|link=OpenSees Example 7. 3D Frame, 3-story 3-bayX 3-bayZ, Reinforced-Concrete Section & Steel W-Section]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*3D frame of fixed geometry | *3D frame of fixed geometry | ||
*nodes and elements are manually manually, one by one | *nodes and elements are manually manually, one by one | ||
Line 526: | Line 586: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*Reinforced-Concrete Section | *Reinforced-Concrete Section | ||
*Steel W-Section | *Steel W-Section | ||
Line 538: | Line 598: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static reversed cyclic analysis | *static reversed cyclic analysis | ||
*dynamic sine-wave input analysis (uniform excitation) | *dynamic sine-wave input analysis (uniform excitation) | ||
Line 553: | Line 613: | ||
|} | |} | ||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 8. generic 3D Frame, NStory NBayX NBayZ, Reinforced-Concrete Section & Steel W-Section]]</h2> | |||
<!-- subSECTION 2 --> | <!-- subSECTION 2 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example8_figure1.GIF|link=OpenSees Example 8. generic 3D Frame, NStory NBayX NBayZ, Reinforced-Concrete Section & Steel W-Section]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*3D frame geometry of variable geometry ( # stories and # bays in X and Z are variables) | *3D frame geometry of variable geometry ( # stories and # bays in X and Z are variables) | ||
*node and element definition is automated | *node and element definition is automated | ||
Line 583: | Line 638: | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*Reinforced-Concrete Section | *Reinforced-Concrete Section | ||
*Steel W-Section | *Steel W-Section | ||
Line 595: | Line 650: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*static reversed cyclic analysis | *static reversed cyclic analysis | ||
*dynamic sine-wave input analysis (uniform excitation) | *dynamic sine-wave input analysis (uniform excitation) | ||
Line 606: | Line 661: | ||
*dynamic earthquake-input analysis (multiple-support excitation) | *dynamic earthquake-input analysis (multiple-support excitation) | ||
*dynamic bidirectional earthquake-input analysis (uniform excitation) | *dynamic bidirectional earthquake-input analysis (uniform excitation) | ||
</div> | </div> | ||
|} | |} | ||
Line 614: | Line 668: | ||
<h1>Section Modeling And Analysis Examples</h1> | |||
<!-- SECTION --> | <!-- SECTION --> | ||
:<h2>[[OpenSees Example 9. Build & Analyze a Section Example]]</h2> | |||
<!-- subSECTION 1 --> | <!-- subSECTION 1 --> | ||
<!-- 4 COLUMNS --> | <!-- 4 COLUMNS --> | ||
{| style="margin:0; background:none;" | {| style="margin:0; background:none;" | ||
<!-- Column 1 image --> | <!-- Column 1 image --> | ||
| style="margin:0; style="width:25%; border:1px solid # | | style="margin:0; style="width:25%; border:1px solid #red; background:#white; vertical-align:top;" | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | | ! style="padding:2px" | | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
[[File:Example9_figure1.GIF|link=OpenSees Example 9. Section Build & Analysis Example]] | |||
</div> | </div> | ||
|} | |} | ||
<!-- Column 2 --> | <!-- Column 2 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Objectives</strong> | ! style="padding:2px" | <strong>Objectives</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*defined section using uniaxial behavior (define moment-curvature curve) or | *defined section using uniaxial behavior (define moment-curvature curve) or | ||
*define section using uniaxial materials (define stress curve) in fiber section | *define section using uniaxial materials (define stress-strain curve) in fiber section | ||
</div> | </div> | ||
|} | |} | ||
<!-- Column 3 --> | <!-- Column 3 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Models</strong> | ! style="padding:2px" | <strong>Models</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*Uniaxial Nonlinear section | *Uniaxial Nonlinear section | ||
*Fiber Steel W-section | *Fiber Steel W-section | ||
Line 659: | Line 709: | ||
|} | |} | ||
<!-- Column 4 --> | <!-- Column 4 --> | ||
| style="margin:0; width:25%; border:1px solid # | | style="margin:0; width:25%; border:1px solid #red; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top; background:#white;" | {| style="width:100%; vertical-align:top; background:#white;" | ||
! style="padding:2px" | <strong>Analyses</strong> | ! style="padding:2px" | <strong>Analyses</strong> | ||
|- | |- | ||
| style="color:#000;" | <div > | | style="color:#000;" | <div> | ||
*2D static unidirectional moment-curvature analysis | *2D static unidirectional moment-curvature analysis | ||
*3D static unidirectional moment-curvature analysis | *3D static unidirectional moment-curvature analysis |
Latest revision as of 21:01, 17 March 2010
Introduction
The examples in this manual are listed in order of simplicity.
NOTE: gravity analysis is always included as part of the model building
Models
The following types of models are represented in these examples:
Elastic Elements
- OpenSees Elastic Beam Column Element
- The elastic, uncoupled, axial and flexural stiffnesses are defined at the element level
- user specifies: E,I,A
Inelastic Elements
- OpenSees Force-Based Beam-Column Element
- Two types of sections
Uniaxial Section
- The inelastic, uncoupled, axial and flexural stiffnesses are defined at the section level
- The OpenSees Uniaxial Section Command is used
- User specifies:
- Axial stiffness A
- Section Moment-Curvature characteristics via the OpenSees UniaxialMaterial Command
Fiber Section
- The section is broken down into fibers where uniaxial materials are defined independently.
- The program calculates the coupled flexural and axial stiffnesses/strength by integrating strains across the section
- The OpenSees Fiber Section Command is used
- User specifies
- Stress-Strain characteristics via the OpenSees UniaxialMaterial Command for all number of materials
- Section geometry via series of Patches and Layers in the fiber section
- Two Section Geometries are presented
- *RC Rectangular Section
- *Standard AISC W section
Lateral Loads
The following types of lateral loads are represented in these examples:
Static Pushover
- Control node is located at the highest floor
- Lateral-load distribution is proportional the the mass distribution along the height of the building
- Static analysis
- Two types
Monotonic Pushover
- One-directional displacement-controlled static lateral loading
Reversed Cyclic Pushover
- One-directional displacement-controlled static lateral loading
- Displacement cycles are imposed in positive and negative direction
Time-Dependent Dynamic Loads
- Transient analysis
- Four types
Uniform Sine-Wave
- Sine-wave acceleration input
- Same acceleration input at all nodes restrained in specified direction
Multiple-Support Sine-Wave
- Sine-wave displacement input
- Different displacements are specified at particular nodes in specified directions
Uniform Earthquake
- Earthquake (from file) acceleration input
- Same acceleration input at all nodes restrained in specified direction
Multiple-Support Earthquake
- Earthquake (from file) displacement input
- Different displacements are specified at particular nodes in specified direction
Bidirectional Earthquake
- Different inputs are specified for two directions
- Same acceleration input at all nodes restrained in specified direction
Simulation Process
Each example script does the following:
Build the model
- model dimensions and degrees-of-freedom
- nodal coordinates
- nodal constraints -- boundary conditions
- nodal masses
- elements and element connectivity
- recorders for output
Define & apply gravity load
- nodal or element load
- static-analysis parameters (tolerances & load increments)
- analyze
- hold gravity loads constant
- reset time to zero
Define and apply lateral load
- load pattern (nodal loads for static analysis, support ground motion for earthquake)
- lateral-analysis parameters (tolerances & displacement/time increments)
- Static Lateral-Load Analysis
- define the displacement increments and displacement path
- Dynamic Lateral-Load Analysis
- define the input motion and all associated parameters, such as scaling and input type
- define analysis duration and time increment
- define damping
- Static Lateral-Load Analysis
- analyze
Introductory Examples
The objective of Example 1a and Example 1b is to give an overview of input-file format in OpenSees using simple scripts.
These scripts do not take advantage of the Tcl scripting capabilities shown in the later examples. However, they do provide starting a place where the input file is similar to that of more familiar Finite-Element Analysis software. Subsequent examples should be used as the basis for user input files.
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Simple Examples of Nonlinear-Models
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2D Structural Modeling & Analysis Examples
These examples take advantage of the Tcl scripting language starting from simple variable substitutions in the initial examples, to the more advanced techniques of array management and logical expressions (if-then statements).
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3D Structural Modeling & Analysis Examples
A few items are new in 3D:
- Additional coordinates need to be considered in defining nodes
- Additional degrees of freedom need to be considered in defining the following:
- nodal constraints (boundary conditions)
- nodal masses
- nodal loads
- The transformation from local element/section coordinates to global system coordinates needs to be specified
- Element loads are specified in local coordinates
- Additional arguments are required for many elements (bending about local-y axis) properties
- Element/Section torsional stiffness needs to be considered
- Rigid floor diaphragms need be included for building models
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Section Modeling And Analysis Examples
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Return to OpenSees User