Multi-Support Excitation Pattern: Difference between revisions

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The Multi-Support pattern allows similar or different prescribed ground motions to be input at various supports in the structure.
The Multi-Support pattern allows similar or different prescribed ground motions to be input at various supports in the structure.
In OpenSees, the prescribed motion is applied using single-point constraints, the single-point constraints taking their constraint value from user created ground motions.
In OpenSees, the prescribed motion is applied using single-point constraints, the single-point constraints taking their constraint value from user created ground motions.
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{| style="background:yellow; color:black; width:800px"  
{| style="background:yellow; color:black; width:800px"  
|''' pattern MultipleSupport $patternTag {''''
| ''' pattern MultipleSupport $patternTag {'''
|-
|-
| '''groundMotion ...'''
| '''[[groundMotion Command | groundMotion]]...'''
|-
|-
| '''imposedMotion ...'''
| '''[[imposedMotion Command | imposedMotion]]...'''
|-
|-
| ''' ... '''
| ''' ... '''
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|  style="width:150px" | '''$patternTag ''' || unique tag among load patterns
|  style="width:150px" | '''$patternTag ''' || unique tag among load patterns
|-
|-
|  '''groundMotion ...''' || command to generate a ground motion  
|  '''[[groundMotion Command| groundMotion]]...''' || command to generate a ground motion  
|-
|-
| '''imposedMotion ...''' || command to generate an imposed motion
| '''[[imposedMotion Command| imposedMotion]] ...''' || command to generate an imposed motion
|}
|}



Latest revision as of 22:09, 2 February 2011




The Multi-Support pattern allows similar or different prescribed ground motions to be input at various supports in the structure. In OpenSees, the prescribed motion is applied using single-point constraints, the single-point constraints taking their constraint value from user created ground motions.

<uml> abstract class TimeSeries LoadPattern <|-- MultipleSupportExcitation MultipleSupportExcitation o- GroundMotion MultipleSupportExcitation o- ImposedMotionSP ImposedMotionSP --- GroundMotion SP_Constraint <|-- ImposedMotionSP GroundMotion o- TimeSeries </uml>

The command to generate a multi-support excitation contains in { } the commands to generate all the ground motions and the single-point constraints in the pattern. The command is as follows:


pattern MultipleSupport $patternTag {
groundMotion...
imposedMotion...
...
}

NOTES:

  1. The results for the responses at the nodes are the ABSOLUTE values, and not relative values as in the case of a UniformExciatation.
  2. The non-homogeneous single point constraints require an appropriate choice of constraint handler.

$patternTag unique tag among load patterns
groundMotion... command to generate a ground motion
imposedMotion ... command to generate an imposed motion




Code Developed by: fmk