Linear Transformation

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chen
Posts: 11
Joined: Tue Apr 12, 2005 8:24 am

Linear Transformation

Post by chen » Mon May 09, 2005 8:48 am

Hi
I am trying to define the orientation of the beam of a 3D frame with Linear Transformation but I don't Know how you get the local axis of the element 2 in the user's manual. I think the y and z local axis in element 2 must be the oposite after do the cross product of the axis x and 0 1 0.

And I have tested and the linear loads works but the direction is the oposite of the local axis.
Here I send you my test file
May you tell me if I am right or not and how it's works ?
Thanks.
wipe
model basic -ndm 3 -ndf 6
set L1 10000
set L2 5000
node 1 0 0 0
node 2 0 $L1 0
node 3 $L2 $L1 0
fix 1 1 1 1 1 1 1
fix 3 1 1 1 1 1 1
set E 7000.416
set A 5956
set J 148750667
set Iz 74375334
set Iy 74375334
set G 2730.9530769231
set v 0.3
geomTransf Linear 1 0 0 1
element elasticBeamColumn 1 1 2 $A $E $G $J $Iy $Iz 1
element elasticBeamColumn 2 2 3 $A $E $G $J $Iy $Iz 1
set W1XPOS 0
set W1XNEG 0
set W2YPOS 0
set W2YNEG 0
set PROPE
set Px1 -9798.2022
set Px2 9798.2022
set Py 0
set Pz 0
set xL1 0
set xL2 1
pattern Plain 1 Linear {
eleLoad -ele 1 2 -type -beamUniform 0 -$PROPE

eleLoad -ele 1 -type -beamUniform -$W1XPOS 0
eleLoad -ele 1 -type -beamUniform $W1XNEG 0
eleLoad -ele 2 -type -beamUniform $W2YPOS 0
eleLoad -ele 2 -type -beamUniform -$W2YNEG 0
eleLoad -ele 1 2 -type -beamPoint $Py $Pz $xL1 $Px1
eleLoad -ele 1 2 -type -beamPoint $Py $Pz $xL2 $Px2
}
system BandGeneral
constraints Transformation
numberer RCM
algorithm Linear
integrator LoadControl 1
analysis Static

analyze 1
print
[/img]

silvia
Posts: 3909
Joined: Tue Jan 11, 2005 7:44 am
Location: Degenkolb Engineers
Contact:

Post by silvia » Mon May 09, 2005 9:13 am

yeah, i think i had the vector pointing in the opposite direction (negative of what it is supposed to be), I'll look into it and fix it.
Silvia Mazzoni, PhD
Structural Consultant
Degenkolb Engineers
235 Montgomery Street, Suite 500
San Francisco, CA. 94104

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