Modeling Commands: Difference between revisions

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Domain o- LoadPattern
Domain o- LoadPattern
</uml>
</uml>


The following are the modeling commands that have been added to OpenSees interpreter to create these components of the finite element model:   
The following are the modeling commands that have been added to OpenSees interpreter to create these components of the finite element model:   
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<uml>
<uml>
package "Element" #DDDDDD
package "Element Classes" #DDDDDD
abstract class Element
abstract class Element
abstract class Material
abstract class Material
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Element o- Material
Element o- Material
Element o- GeometricTransformation
Element o- GeometricTransformation
Material <|-- UniaxialMaterial
Material <|-- UniaxialMaterial
Material <|-- SectionForceDeformation
Material <|-- SectionForceDeformation
Material <|-- NDMaterial
Material <|-- NDMaterial
</uml>
</uml>



Revision as of 00:16, 23 September 2010




The model or domain in OpenSees is a collection (an aggregation in object-oriented terms) of elements, nodes, single- and multi-point constraints and load patterns. It is the aggregation of these components which define the type of model that is being analyzed. The component classes, are as shown in the figure below:

<uml> package "OpenSees Model" #DDDDDD

abstract class Element Domain o- Element Domain o- Node Domain o- SP_Constraint Domain o- MP_Constraint Domain o- LoadPattern </uml>


The following are the modeling commands that have been added to OpenSees interpreter to create these components of the finite element model:

  • model
  • element
  • node
  • SP_Constraint (single-point constraint), which prescribe the movement (typically 0) of a single dof at a node. There are a number of commands for creating single-point coonstraints:
  • MP_Constraint (multi-point constraint), which prescribe that the movement of certain dof at one node are defined by the movement of certain dof at another node. There again are a number of commands for defining multi-point constraints.
  • timeSeries
  • pattern




The following Misc commands are used to generate elementts or modify properties of elements or nodes already in the model:



The typical element in OpenSees has the material nonlinearity and sometimes geometric nonlinearities contained in other objects, materials and geometric transformations. Commands have been added to the interpreter to create these objects as well:

<uml> package "Element Classes" #DDDDDD abstract class Element abstract class Material abstract class UniaxialMaterial abstract class NDMaterial abstract class SectionForceDeformation abstract class GeometricTransformation

Element o- Material Element o- GeometricTransformation

Material <|-- UniaxialMaterial Material <|-- SectionForceDeformation Material <|-- NDMaterial </uml>


  1. uniaxial Material
  2. ND Material
  3. Section
  4. friction Model
  5. geometricTransf