Help analysis two load history

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Oreste
Posts: 12
Joined: Fri Jan 22, 2010 5:20 am
Location: Roma

Help analysis two load history

Post by Oreste »

I have the following model:

# --------------------------------------------------------------------------------------------------
# Trave 2 Modello Elastico
# elasticBeamColumn element
# Unità in KN, cm
#
# 1 ----------------------- 2 -------- 3
# L1 L2
# ^Y
# |
# |
# |
# |
# ------------- >X
#

# SET UP ----------------------------------------------------------------------------------------
wipe; # clear opensees model
model basic -ndm 2 -ndf 3; # 2 dimensions, 3 dof per node
set dataDir Data3; # set up name for data directory
file mkdir $dataDir/; # create data directory

# definizione geoemtria -------------------------------------------------------------
set L1 423; # luce campata
set L2 219.5; # luce sbalzo
set Lp1 85.8; # posizione potenziometro campata sxsx (a partire dall'appoggio del nodo 1)
set Lp2 170.5; # posizione potenziometro campata sx (a partire dall'appoggio del nodo 1)
set Lp3 255.3; # posizione potenziometro campata c (a partire dall'appoggio del nodo 1)
set Lp4 339.1; # posizione potenziometro campata dx (a partire dall'appoggio del nodo 1)
set Lp5 109.8; # posizione potenziometro sbalzo mc (a partire dall'appoggio del nodo 6)
set Lp6 109.7; # posizione potenziometro sbalzo me (a partire dall'appoggio del nodo 6)

# definizione sezione
set H 52; # Altezza sezione
set B 26; # Base inferiore
set Bali 58; # Base suoperiore
set h 20; # Altezza zona piena

# calcolo caratteristiche geometriche e meccaniche
set Aomog 2263.43; # Area sezione omogeneizzata
set Izcampata 574422.11; # Momento di inerzia omogeneizzato sezione campata
set Izsbalzo 536396.35; # Momento di inerzia omogeneizzato sezione sbalzo
set E 2000; # Modulo elastico calcestruzzo

# coordinate nodali x,y
node 1 0 0;
node 2 $Lp1 0;
node 3 $Lp2 0;
node 4 $Lp3 0;
node 5 $Lp4 0;
node 6 $L1 0;
node 7 [expr $L1+$Lp5] 0;
node 8 [expr $L1+$L2] 0;

# Single point constraints -- Boundary Conditions
fix 1 1 1 0; # node DX DY RZ
fix 6 0 1 0; # node DX DY RZ


# Define ELEMENTS -------------------------------------------------------------
# define geometric transformation: performs a linear geometric transformation of beam stiffness and resisting force from the basic system to the global-coordinate system
set transfTag 1;
geomTransf Linear $transfTag; # associate a tag to transformation

# connectivity:
element elasticBeamColumn 1 1 2 $Aomog $E $Izcampata $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 2 2 3 $Aomog $E $Izcampata $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 3 3 4 $Aomog $E $Izcampata $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 4 4 5 $Aomog $E $Izcampata $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 5 5 6 $Aomog $E $Izcampata $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 6 6 7 $Aomog $E $Izsbalzo $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag
element elasticBeamColumn 7 7 8 $Aomog $E $Izsbalzo $transfTag; # element elasticBeamColumn $eleTag $iNode $jNode $A $E $Iz $transfTag


# Define RECORDERS -------------------------------------------------------------
recorder Node -file Data3/Dispnodo2.txt -time -node 2 -dof 1 2 3 disp; # spostamenti nodo 2
recorder Node -file Data3/Dispnodo3.txt -time -node 3 -dof 1 2 3 disp; # spostamenti nodo 3
recorder Node -file Data3/Dispnodo4.txt -time -node 4 -dof 1 2 3 disp; # spostamenti nodo 4
recorder Node -file Data3/Dispnodo5.txt -time -node 5 -dof 1 2 3 disp; # spostamenti nodo 5
recorder Node -file Data3/Dispnodo7.txt -time -node 7 -dof 1 2 3 disp; # spostamenti nodo 7
recorder Node -file Data3/Dispnodo8.txt -time -node 8 -dof 1 2 3 disp; # spostamenti nodo 8

recorder Node -file Data3/RBase1.txt -time -node 1 -dof 1 2 3 reaction; # support reaction
recorder Node -file Data3/RBase2.txt -time -node 6 -dof 1 2 3 reaction; # support reaction


# Definizione analisi statica

# The displacement is applied using the sp command, the command requires the node and
# DOF of interest. A reference values is given that is multiplied by the displacements
# in the Pathseries to determine the applied displacement.

set F1 " Series -dt 0.1 -values {32.00 36.00 45.00 51.00 60.00 66.00 80.00 87.00 50.00}";
set F2 " Series -dt 0.1 -values {0.00 9.00 9.00 18.00 18.00 27.00 27.00 36.00 0.00}"

pattern Plain 1 $F1 {

load 4 0 -1 0
}

pattern Plain 2 $F2 {
load 8 0 -1 0
}

# Define analysis parameters
integrator LoadControl 1
system SparseGeneral -piv
test NormDispIncr 1.0e-5 100 1
numberer Plain
constraints Transformation
algorithm KrylovNewton
analysis Static

# Apply the 1 points in the files.
analyze 1

# create the display
recorder display Trave 10 10 800 200 -wipe
prp 0 0 100.0
vup 0 1 0
vpn 0 0 1
viewWindow -500 500 -200 200
projection 0
display 1 0 10

puts "Beam Done"

When I turn I take no step load

Someone tell me why? Thank you, answer there I would be grateful
fmk
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Joined: Fri Jun 11, 2004 2:33 pm
Location: UC Berkeley
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Post by fmk »

you are using LoadControl with a step of 1.0, the dt in your series is 0.1 .. if you do 1 step it sets the time in the domain to 1.0. at 1.0 your timeseries will report back that the load factor is 0.0 because you don't have 10 pts in the array!
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