Corotational Truss Element: Difference between revisions

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{|  
{|  
| style="background:yellow; color:black; width:800px" | '''element corotTruss $eleTag $iNode $jNode $A $matTag <-rho $rho> <-doRayleigh $rFlag>'''
| style="background:lime; color:black; width:800px" | '''element corotTruss $eleTag $iNode $jNode $A $matTag <-rho $rho> <-cMass $cFlag> <-doRayleigh $rFlag>'''
|}
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{|  
{|  
| style="background:yellow; color:black; width:800px" | '''element corotTrussSection $eleTag $iNode $jNode $secTag <-rho $rho> <-doRayleigh $rFlag>'''
| style="background:lime; color:black; width:800px" | '''element corotTrussSection $eleTag $iNode $jNode $secTag <-rho $rho> <-cMass $cFlag> <-doRayleigh $rFlag>'''
|}
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| '''$secTag''' || tag associated with previously-defined Section
| '''$secTag''' || tag associated with previously-defined Section
|-
|-
| '''$rho''' || optional, mass per unit length, default = 0.0
| '''$rho''' || mass per unit length, optional, default = 0.0
|-
|-
| '''$rFlag''' || optional, default = 0
| '''$cFlag''' || consistent mass flag, optional, default = 0
|-
| || cFlag = 0 lumped mass matrix (default)
|-
| || cFlag = 1 consistent mass matrix
|-
| '''$rFlag''' || Rayleigh damping flag, optional, default = 0
|-
|-
| || rFlag = 0 NO RAYLEIGH DAMPING (default)
| || rFlag = 0 NO RAYLEIGH DAMPING (default)
|-
|-
| ||   rFlag = 1 include rayleigh damping
| || rFlag = 1 include Rayleigh damping
|}
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*For backward compatability the command '''element corotTruss $eleTag $iNode $jNode $secTag'' will still work and produce a CorotTrussSection element.
*For backward compatability the command '''element corotTruss $eleTag $iNode $jNode $secTag'' will still work and produce a CorotTrussSection element.


* There was an inconsistancy in the way damping was treated between element types before version 2.2.0. Before 2.2.0, a CorotTruss DID NOT INCLUDE rayleigh damping, a CorotTrussSection did. By default they both DO NOT now include rayleigh damping by default.
*CorotTruss DOES NOT include Rayleigh damping by default.


EXAMPLE:
EXAMPLE:
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----
----


Code Developed by: <span style="color:blue"> fmk </span>
Code Developed by: <span style="color:blue"> Michael H. Scott, Oregon State University </span>

Latest revision as of 01:56, 22 August 2014



This command is used to construct a corotational truss element object. There are two ways to construct a corotational truss element object:

One way is to specify an area and a UniaxialMaterial identifier:

element corotTruss $eleTag $iNode $jNode $A $matTag <-rho $rho> <-cMass $cFlag> <-doRayleigh $rFlag>


the other is to specify a Section identifier:

element corotTrussSection $eleTag $iNode $jNode $secTag <-rho $rho> <-cMass $cFlag> <-doRayleigh $rFlag>



$eleTag unique element object tag
$iNode $jNode end nodes
$A cross-sectional area of element
$matTag tag associated with previously-defined UniaxialMaterial
$secTag tag associated with previously-defined Section
$rho mass per unit length, optional, default = 0.0
$cFlag consistent mass flag, optional, default = 0
cFlag = 0 lumped mass matrix (default)
cFlag = 1 consistent mass matrix
$rFlag Rayleigh damping flag, optional, default = 0
rFlag = 0 NO RAYLEIGH DAMPING (default)
rFlag = 1 include Rayleigh damping


NOTE:

  • When constructed with a UniaxialMaterial object, the corotational truss element considers strain-rate effects, and is thus suitable for use as a damping element.
  • The valid queries to a truss element when creating an ElementRecorder object are 'axialForce,' 'stiff,' deformations,' 'material matArg1 matArg2...,' 'section sectArg1 sectArg2...' There will be more queries after the interface for the methods involved have been developed further.
  • For backward compatability the command 'element corotTruss $eleTag $iNode $jNode $secTag will still work and produce a CorotTrussSection element.
  • CorotTruss DOES NOT include Rayleigh damping by default.

EXAMPLE:

element truss 1 2 4 5.5 9; # truss element with tag 1 added between nodes 2 and 4 with area 5.5 that uses material 9

Code Developed by: Michael H. Scott, Oregon State University

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