OpenSees Example 9. Build & Analyze a Section Example: Difference between revisions
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<h3> | <h3>Moment-Curvature Analysis</h3> | ||
*This example introduces the moment-curvature procedures for sections in 2D or 3D space, as built in the previous section. (the only difference between them is the degree-of-freedom corresponding to curvature). | |||
*The moment-curvature analysis of a section is by creating a zero-length rotational-spring element. This section is subjected to a user-defined constant axial load and to a linearly-increasing moment to a user-defined maximum curvature. | |||
* | |||
{| style="margin:0; background:none;" | {| style="margin:0; background:none; border:3px solid #ccc;" | ||
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| style="margin:0; width:25%; | | style="margin:0; width:25%; background:#white; vertical-align:top; " | | ||
{| style="width:100%; vertical-align:top;background:#white;" | |||
{| style="width:100% | <h4>2D Moment-Curvature Analysis</h4> | ||
|- | |- | ||
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{| style="width:100%; vertical-align:top;background:#white;" | |||
<strong>Files</strong> | <strong>Files</strong> | ||
*[[Media: | *[[Media:Ex9.analyze.MomentCurvature2D.tcl|Ex9.analyze.MomentCurvature2D.tcl]] | ||
*[[Media: | *[[Media:MomentCurvature2D.tcl|MomentCurvature2D.tcl]] | ||
---- | |} | ||
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<strong>Notes</strong> | <strong>Notes</strong> | ||
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<h4>3D Moment-Curvature Analysis</h4> | |||
|- | |- | ||
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<strong>Files</strong> | <strong>Files</strong> | ||
*[[Media: | *[[Media:Ex9.analyze.MomentCurvature3D.tcl|Ex9.analyze.MomentCurvature3D.tcl]] | ||
*[[Media: | *[[Media:MomentCurvature3D.tcl|MomentCurvature3D.tcl]] | ||
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<strong>Notes</strong> | <strong>Notes</strong> | ||
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==Run== | ==Run== | ||
The model and analysis combinations for this example are numerous. The following are an small subset, for demonstration purposes: | The model and analysis combinations for this example are numerous. The following are an small subset, for demonstration purposes: | ||
* To run | * To run Uniaxial-Section Model, 2D | ||
<blockquote><source lang="Tcl"> | <blockquote><source lang="Tcl"> | ||
puts " ------------- | puts " --------------------------------- 2D Model ---------------" | ||
puts " a. Uniaxial Section" | |||
source | source Ex9a.build.UniaxialSection2D.tcl | ||
source | source Ex9.analyze.MomentCurvature2D.tcl | ||
</source></blockquote> | </source></blockquote> | ||
* To run RC Model, | * To run RC Section: Rectangular, Confined, Symmetric Model, 3D | ||
<blockquote><source lang="Tcl"> | <blockquote><source lang="Tcl"> | ||
puts " ------------- | puts " --------------------------------- 3D Model ---------------" | ||
puts " d. RC Section: Rectangular, Confined, Symmetric" | |||
source | source Ex9d.build.RCSection.RectConfinedSymm3D.tcl | ||
source | source Ex9.analyze.MomentCurvature3D.tcl | ||
</source></blockquote> | </source></blockquote> | ||
==Notes== | ==Notes== | ||
Revision as of 22:24, 11 November 2009
Introduction
For the case of the uniaxial section, moment-curvature and axial force-deformation curves are defined independently, and numerically.
For the case of the fiber sections (steel and RC), uniaxial materials are defined numerically (stress-strain relationship) and are combined into a fiber section where moment-curvature and axial force-deformation characteristics and their interaction are calculated computationally.
Input
Model Building
- 2D vs. 3D
- While this distinction does not affect the section definition itself, it affects the degree-of-freedom associated with moment and curvature in the subsequent analysis.
- There are two differences between the two models:
- 1. The space defined with the model command (# Define the model builder, ndm=#dimension, ndf=#dofs)
- 2D
- model BasicBuilder -ndm 2 -ndf 3;
- 3D
- model BasicBuilder -ndm 3 -ndf 6;
- 2. In the 3D model, torsional stiffness needs to be aggregated to the section
- 1. The space defined with the model command (# Define the model builder, ndm=#dimension, ndf=#dofs)
Uniaxial Section
Files Notes - Flexure and axial behavior are uncoupled in this type of section
Fiber Section: AISC Standard W Section
Files Notes - Coupled biaxial flexure and axial behavior
Fiber Section: Reinforced Concrete Section -- Rectangular Symmetric Section, Unconfined Concrete
Files Notes - Coupled biaxial flexure and axial behavior
Fiber Section: Reinforced Concrete Section -- Rectangular Symmetric Section, Confined Concrete Core
Files Notes - Coupled biaxial flexure and axial behavior
Fiber Section: Reinforced Concrete Section -- Rectangular Section
Files Notes - Coupled biaxial flexure and axial behavior
- generic rectangular section
Fiber Section: Reinforced Concrete Section -- Circular Section, Confined Core
Files Notes - Coupled biaxial flexure and axial behavior
- generic circular section
Moment-Curvature Analysis
- This example introduces the moment-curvature procedures for sections in 2D or 3D space, as built in the previous section. (the only difference between them is the degree-of-freedom corresponding to curvature).
- The moment-curvature analysis of a section is by creating a zero-length rotational-spring element. This section is subjected to a user-defined constant axial load and to a linearly-increasing moment to a user-defined maximum curvature.
2D Moment-Curvature Analysis
Files Notes 3D Moment-Curvature Analysis
Files Notes
Run
The model and analysis combinations for this example are numerous. The following are an small subset, for demonstration purposes:
- To run Uniaxial-Section Model, 2D
puts " --------------------------------- 2D Model ---------------" puts " a. Uniaxial Section" source Ex9a.build.UniaxialSection2D.tcl source Ex9.analyze.MomentCurvature2D.tcl
- To run RC Section: Rectangular, Confined, Symmetric Model, 3D
puts " --------------------------------- 3D Model ---------------" puts " d. RC Section: Rectangular, Confined, Symmetric" source Ex9d.build.RCSection.RectConfinedSymm3D.tcl source Ex9.analyze.MomentCurvature3D.tcl
Notes
Return to OpenSees Examples Manual -- Structural Models & Analyses
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