Receiving error when using Joint2D

littlelam87 · Post by **littlelam87** » Fri Jun 25, 2010 3:10 pm

Hi,
I am trying to use the element Joint2D to model a steel MF panel zone. I basically followed the command on Altoontash Dissertaiton. However, OpenSees kept on saying "constraint matrix not diagonal". I am not sure how to fix this problem.
Then, I went onto trying the beamColumnJoint element documented on the OpenSees website, using very stiff uniaxial elastic material for Materal 1 through Material 12 since there's no bar slippage. For both Joint2D and beamColumnJoint element, I used the same material to simulate the shear strength of the panel zone. With the beamCOlumnJoint element, the fundamental period of the structure is about 6.4 seconds, which is way longer than the model w/o panel zone, and does not make sense.
It would be great if you can advice me as to possible errors I have made in my code and modeling.
Many thanks

Post by **fmk** » Sat Jun 26, 2010 1:37 am

Try a different constraint handler. Plain only deals with identity matrix.

e.kian · Post by **e.kian** » Sat Jun 26, 2010 1:07 pm

If you send for me your script I will try to solve your problem.
but you must use penalty or Transformation instead of plain as stated in Arash thesis.

littlelam87 · Post by **littlelam87** » Mon Jun 28, 2010 9:29 am

#######Define Model#######

model BasicBuilder -ndm 2 -ndf 3
geomTransf Linear 1;
geomTransf PDelta 2;
source LibUnits.tcl;
set Tol 1.0e-8; # convergence tolerance for test

#######Nodal Geometry#######
node 1 0 0 -mass 1.00E-09 0 0
node 2 0 171.05 -mass 0.209411663 0 0
node 3 8.95 180 -mass 1.00E-09 0 0
node 4 0 188.95 -mass 1.00E-09 0 0
node 5 -8.95 180 -mass 0.209411663 0 0
node 6 0 343.45 -mass 0.207470669 0 0
node 7 8.95 360 -mass 1.00E-09 0 0
node 8 0 376.55 -mass 1.00E-09 0 0
node 9 -8.95 360 -mass 0.207470669 0 0
node 10 0 526.45 -mass 0.214803313 0 0
node 11 7.85 540 -mass 1.00E-09 0 0
node 12 0 553.55 -mass 1.00E-09 0 0
node 13 -7.85 540 -mass 0.214803313 0 0
node 14 360 0 -mass 1.00E-09 0 0
node 15 360 171.05 -mass 0.209411663 0 0
node 16 368.95 180 -mass 1.00E-09 0 0
node 17 360 188.95 -mass 1.00E-09 0 0
node 18 351.05 180 -mass 0.209411663 0 0
node 19 360 343.45 -mass 0.207470669 0 0
node 20 368.95 360 -mass 1.00E-09 0 0
node 21 360 376.55 -mass 1.00E-09 0 0
node 22 351.05 360 -mass 0.207470669 0 0
node 23 360 526.45 -mass 0.214803313 0 0
node 24 367.85 540 -mass 1.00E-09 0 0
node 25 360 553.55 -mass 1.00E-09 0 0
node 26 352.15 540 -mass 0.214803313 0 0
node 27 720 0 -mass 1.00E-09 0 0
node 28 720 171.05 -mass 0.209411663 0 0
node 29 728.95 180 -mass 1.00E-09 0 0
node 30 720 188.95 -mass 1.00E-09 0 0
node 31 711.05 180 -mass 0.209411663 0 0
node 32 720 343.45 -mass 0.207470669 0 0
node 33 728.95 360 -mass 1.00E-09 0 0
node 34 720 376.55 -mass 1.00E-09 0 0
node 35 711.05 360 -mass 0.207470669 0 0
node 36 720 526.45 -mass 0.214803313 0 0
node 37 727.85 540 -mass 1.00E-09 0 0
node 38 720 553.55 -mass 1.00E-09 0 0
node 39 712.15 540 -mass 0.214803313 0 0
node 40 1080 0 -mass 1.00E-09 0 0
node 41 1080 171.05 -mass 0.209411663 0 0
node 42 1088.95 180 -mass 1.00E-09 0 0
node 43 1080 188.95 -mass 1.00E-09 0 0
node 44 1071.05 180 -mass 0.209411663 0 0
node 45 1080 343.45 -mass 0.207470669 0 0
node 46 1088.95 360 -mass 1.00E-09 0 0
node 47 1080 376.55 -mass 1.00E-09 0 0
node 48 1071.05 360 -mass 0.207470669 0 0
node 49 1080 526.45 -mass 0.214803313 0 0
node 50 1087.85 540 -mass 1.00E-09 0 0
node 51 1080 553.55 -mass 1.00E-09 0 0
node 52 1072.15 540 -mass 0.214803313 0 0
node 53 1440 0 -mass 1.00E-09 0 0
node 54 1440 171.05 -mass 0.209411663 0 0
node 55 1448.95 180 -mass 1.00E-09 0 0
node 56 1440 188.95 -mass 1.00E-09 0 0
node 57 1431.05 180 -mass 0.209411663 0 0
node 58 1440 343.45 -mass 0.207470669 0 0
node 59 1448.95 360 -mass 1.00E-09 0 0
node 60 1440 376.55 -mass 1.00E-09 0 0
node 61 1431.05 360 -mass 0.207470669 0 0
node 62 1440 526.45 -mass 0.214803313 0 0
node 63 1447.85 540 -mass 1.00E-09 0 0
node 64 1440 553.55 -mass 1.00E-09 0 0
node 65 1432.15 540 -mass 0.214803313 0 0
node 66 1800 0 -mass 1.00E-09 0 0
node 67 1800 171.05 -mass 0.209411663 0 0
node 68 1808.95 180 -mass 1.00E-09 0 0
node 69 1800 188.95 -mass 1.00E-09 0 0
node 70 1791.05 180 -mass 0.209411663 0 0
node 71 1800 343.45 -mass 0.207470669 0 0
node 72 1808.95 360 -mass 1.00E-09 0 0
node 73 1800 376.55 -mass 1.00E-09 0 0
node 74 1791.05 360 -mass 0.207470669 0 0
node 75 1800 526.45 -mass 0.214803313 0 0
node 76 1807.85 540 -mass 1.00E-09 0 0
node 77 1800 553.55 -mass 1.00E-09 0 0
node 78 1792.15 540 -mass 0.214803313 0 0

#######Boundary Conditions#######
fix 1 1 1 1;
fix 5 1 1 1;
fix 9 1 1 1;
fix 13 1 1 1;
fix 17 1 1 1;
fix 21 1 1 1;

#######Beam Column Elements#######

source PZelem.tcl; #generate panel zone element using Joint2D

element elasticBeamColumn 1 1 2 109 29000 5440 1
element elasticBeamColumn 2 4 6 109 29000 5440 1
element elasticBeamColumn 3 8 10 62 29000 2660 1
element elasticBeamColumn 4 14 15 109 29000 5440 1
element elasticBeamColumn 5 17 19 109 29000 5440 1
element elasticBeamColumn 6 21 23 62 29000 2660 1
element elasticBeamColumn 7 27 28 109 29000 5440 1
element elasticBeamColumn 8 30 32 109 29000 5440 1
element elasticBeamColumn 9 34 36 62 29000 2660 1
element elasticBeamColumn 10 40 41 109 29000 5440 1
element elasticBeamColumn 11 43 45 109 29000 5440 1
element elasticBeamColumn 12 47 49 62 29000 2660 1
element elasticBeamColumn 13 53 54 109 29000 5440 1
element elasticBeamColumn 14 56 58 109 29000 5440 1
element elasticBeamColumn 15 60 62 62 29000 2660 1
element elasticBeamColumn 16 66 67 109 29000 5440 1
element elasticBeamColumn 17 69 71 109 29000 5440 1
element elasticBeamColumn 18 73 75 62 29000 2660 1
element elasticBeamColumn 19 3 18 41.6 29000 7450 1
element elasticBeamColumn 20 7 22 38.3 29000 6710 1
element elasticBeamColumn 21 11 26 30 29000 3620 1
element elasticBeamColumn 22 16 31 41.6 29000 7450 1
element elasticBeamColumn 23 20 35 38.3 29000 6710 1
element elasticBeamColumn 24 24 39 30 29000 3620 1
element elasticBeamColumn 25 29 44 41.6 29000 7450 1
element elasticBeamColumn 26 33 48 38.3 29000 6710 1
element elasticBeamColumn 27 37 52 30 29000 3620 1
element elasticBeamColumn 28 42 57 41.6 29000 7450 1
element elasticBeamColumn 29 46 61 38.3 29000 6710 1
element elasticBeamColumn 30 50 65 30 29000 3620 1
element elasticBeamColumn 31 55 70 41.6 29000 7450 1
element elasticBeamColumn 32 59 74 38.3 29000 6710 1
element elasticBeamColumn 33 63 78 30 29000 3620 1

#######Eigen Analysis#######
source EigAnalysis.tcl

################### STATIC ANALYSIS
#source grav.tcl

pattern Plain 1 Linear {
load 2 0 -84.55 0
load 3 0 -84.1 0
load 4 0 -85.8 0
load 6 0 -84.55 0
load 7 0 -84.1 0
load 8 0 -85.8 0
load 10 0 -84.55 0
load 11 0 -84.1 0
load 12 0 -85.8 0
load 14 0 -84.55 0
load 15 0 -84.1 0
load 16 0 -85.8 0
load 18 0 -84.55 0
load 19 0 -84.1 0
load 20 0 -85.8 0
load 22 0 -84.55 0
load 23 0 -84.1 0
load 24 0 -85.8 0

}
system UmfPack;
constraints Transformation;
#constraints Penalty;
test NormDispIncr 1.0e-5 10 0;
algorithm Newton;
numberer RCM;
integrator LoadControl 0.1;
analysis Static;
initialize;
analyze 10;
loadConst -time 0.0;
puts "gravity load on"

littlelam87 · Post by **littlelam87** » Mon Jun 28, 2010 9:31 am

#PZelem.tcl PANELZONE MODELLING

set kes1 9273149.782
set kes2 9210004.766
set kes3 4021841.983

set b 0.03

uniaxialMaterial ElasticPP 101 $kes1 0.002588122
uniaxialMaterial ElasticPP 201 $kes2 0.002588122
uniaxialMaterial ElasticPP 301 $kes3 0.002588122

uniaxialMaterial Steel01 102 12842.214 1240495.475 $b
uniaxialMaterial Steel01 202 12842.214 1240495.475 $b
uniaxialMaterial Steel01 302 4229.5968 408558.5001 $b

uniaxialMaterial Parallel 103 101 102
uniaxialMaterial Parallel 203 201 202
uniaxialMaterial Parallel 303 301 302

# for beamColumnJoint Element
uniaxialMaterial Elastic 300 1000000000000

puts "PZ Material Built"

set LargeDisp 0

element Joint2D 101 2 3 4 5 101 300 300 300 300 103 $LargeDisp
element Joint2D 201 6 7 8 9 102 300 300 300 300 203 $LargeDisp
element Joint2D 301 10 11 12 13 103 300 300 300 300 303 $LargeDisp
element Joint2D 102 15 16 17 18 104 300 300 300 300 103 $LargeDisp
element Joint2D 202 19 20 21 22 105 300 300 300 300 203 $LargeDisp
element Joint2D 302 23 24 25 26 106 300 300 300 300 303 $LargeDisp
element Joint2D 103 28 29 30 31 107 300 300 300 300 103 $LargeDisp
element Joint2D 203 32 33 34 35 108 300 300 300 300 203 $LargeDisp
element Joint2D 303 36 37 38 39 109 300 300 300 300 303 $LargeDisp
element Joint2D 104 41 42 43 44 110 300 300 300 300 103 $LargeDisp
element Joint2D 204 45 46 47 48 111 300 300 300 300 203 $LargeDisp
element Joint2D 304 49 50 51 52 112 300 300 300 300 303 $LargeDisp
element Joint2D 105 54 55 56 57 113 300 300 300 300 103 $LargeDisp
element Joint2D 205 58 59 60 61 114 300 300 300 300 203 $LargeDisp
element Joint2D 305 62 63 64 65 115 300 300 300 300 303 $LargeDisp
element Joint2D 106 67 68 69 70 116 300 300 300 300 103 $LargeDisp
element Joint2D 206 71 72 73 74 117 300 300 300 300 203 $LargeDisp
element Joint2D 306 75 76 77 78 118 300 300 300 300 303 $LargeDisp

littlelam87 · Post by **littlelam87** » Mon Jun 28, 2010 9:39 am

Thanks for you guys' help. I really appreciate it.

I have posted the code that is giving me the error. If I do not run any static or dynamic analysis, OpenSees works well. Using very high stiffness for Material 1 through 4 and a rotational spring for the central node in forming the element joint2D, OpenSees is giving me T1 = 1.2 sec as opposed to T1 = 0.79 sec without the panel zone. Is this normal? Usually, how far off the fundamental period T1 is affected by modelling the panel zone?

Also, when I am using transformation for my constraints, OpenSees just closes on me. Is there something I can do to fix the problem? When I try using Penalty constraint, it requires an alpha factor that I am sure what the appropriate value should be. Do you think you can give me some advice on the alpha factor?

Thanks for your help.

adampaul · Post by **adampaul** » Thu Sep 16, 2010 6:35 am

thanks very much for the clarification provided.