Problems of using shellMITC4 element

[wangfei0330]

Hello, everyone!
I tried to use shellMITC4 element to simulate the safe shell (a 3D model with cylinder below and roof above ) and to do the transient analysis. However, I found that the acceleraions of top points on the model in each direction are incredibly large and seem not to be convergent. Could someone tell me that what is going wrong. Thanks a lot.
Here's my code.

# Definition of model------------------------------------------
model basic -ndm 3 -ndf 6
# Definition of node-------------------------------------------
node 1 2000 0 0
node 2 1847.76 765.37 0
node 3 1847.76 765.37 1000
node 4 2000 0 1000
node 5 1414.21 1414.21 0
node 6 1414.21 1414.21 1000
node 7 765.37 1847.76 0
node 8 765.37 1847.76 1000
node 9 1.225E-13 2000 0
node 10 1.225E-13 2000 1000
node 11 -765.37 1847.76 0
node 12 -765.37 1847.76 1000
node 13 -1414.21 1414.21 0
node 14 -1414.21 1414.21 1000
node 15 -1847.76 765.37 0
node 16 -1847.76 765.37 1000
node 17 -2000 2.449E-13 0
node 18 -2000 2.449E-13 1000
node 19 -1847.76 -765.37 0
node 20 -1847.76 -765.37 1000
node 21 -1414.21 -1414.21 0
node 22 -1414.21 -1414.21 1000
node 23 -765.37 -1847.76 0
node 24 -765.37 -1847.76 1000
node 25 -3.674E-13 -2000 0
node 26 -3.674E-13 -2000 1000
node 27 765.37 -1847.76 0
node 28 765.37 -1847.76 1000
node 29 1414.21 -1414.21 0
node 30 1414.21 -1414.21 1000
node 31 1847.76 -765.37 0
node 32 1847.76 -765.37 1000
node 33 1847.76 765.37 2000
node 34 2000 0 2000
node 35 1414.21 1414.21 2000
node 36 765.37 1847.76 2000
node 37 1.225E-13 2000 2000
node 38 -765.37 1847.76 2000
node 39 -1414.21 1414.21 2000
node 40 -1847.76 765.37 2000
node 41 -2000 2.449E-13 2000
node 42 -1847.76 -765.37 2000
node 43 -1414.21 -1414.21 2000
node 44 -765.37 -1847.76 2000
node 45 -3.674E-13 -2000 2000
node 46 765.37 -1847.76 2000
node 47 1414.21 -1414.21 2000
node 48 1847.76 -765.37 2000
node 49 1847.76 765.37 3000
node 50 2000 0 3000
node 51 1414.21 1414.21 3000
node 52 765.37 1847.76 3000
node 53 1.225E-13 2000 3000
node 54 -765.37 1847.76 3000
node 55 -1414.21 1414.21 3000
node 56 -1847.76 765.37 3000
node 57 -2000 2.449E-13 3000
node 58 -1847.76 -765.37 3000
node 59 -1414.21 -1414.21 3000
node 60 -765.37 -1847.76 3000
node 61 -3.674E-13 -2000 3000
node 62 765.37 -1847.76 3000
node 63 1414.21 -1414.21 3000
node 64 1847.76 -765.37 3000
node 65 1847.76 765.37 4000
node 66 2000 0 4000
node 67 1414.21 1414.21 4000
node 68 765.37 1847.76 4000
node 69 1.225E-13 2000 4000
node 70 -765.37 1847.76 4000
node 71 -1414.21 1414.21 4000
node 72 -1847.76 765.37 4000
node 73 -2000 2.449E-13 4000
node 74 -1847.76 -765.37 4000
node 75 -1414.21 -1414.21 4000
node 76 -765.37 -1847.76 4000
node 77 -3.674E-13 -2000 4000
node 78 765.37 -1847.76 4000
node 79 1414.21 -1414.21 4000
node 80 1847.76 -765.37 4000
node 81 1293.43 535.76 4680
node 82 1400 0 4680
node 83 989.95 989.95 4680
node 84 535.76 1293.43 4680
node 85 8.572E-14 1400 4680
node 86 -535.76 1293.43 4680
node 87 -989.95 989.95 4680
node 88 -1293.43 535.76 4680
node 89 -1400 1.714E-13 4680
node 90 -1293.43 -535.76 4680
node 91 -989.95 -989.95 4680
node 92 -535.76 -1293.43 4680
node 93 -2.572E-13 -1400 4680
node 94 535.76 -1293.43 4680
node 95 989.95 -989.95 4680
node 96 1293.43 -535.76 4680
node 97 739.1 306.15 5120
node 98 800 0 5120
node 99 565.69 565.69 5120
node 100 306.15 739.1 5120
node 101 4.898E-14 800 5120
node 102 -306.15 739.1 5120
node 103 -565.69 565.69 5120
node 104 -739.1 306.15 5120
node 105 -800 9.797E-14 5120
node 106 -739.1 -306.15 5120
node 107 -565.69 -565.69 5120
node 108 -306.15 -739.1 5120
node 109 -1.47E-13 -800 5120
node 110 306.15 -739.1 5120
node 111 565.69 -565.69 5120
node 112 739.1 -306.15 5120
node 113 184.78 76.54 5320
node 114 200 0 5320
node 115 141.42 141.42 5320
node 116 76.54 184.78 5320
node 117 1.225E-14 200 5320
node 118 -76.54 184.78 5320
node 119 -141.42 141.42 5320
node 120 -184.78 76.54 5320
node 121 -200 2.449E-14 5320
node 122 -184.78 -76.54 5320
node 123 -141.42 -141.42 5320
node 124 -76.54 -184.78 5320
node 125 -3.674E-14 -200 5320
node 126 76.54 -184.78 5320
node 127 141.42 -141.42 5320
node 128 184.78 -76.54 5320

# Definition of boundary--------------------------------------------
fix 1 1 1 1 1 1 1
fix 2 1 1 1 1 1 1
fix 5 1 1 1 1 1 1
fix 7 1 1 1 1 1 1
fix 9 1 1 1 1 1 1
fix 11 1 1 1 1 1 1
fix 13 1 1 1 1 1 1
fix 15 1 1 1 1 1 1
fix 17 1 1 1 1 1 1
fix 19 1 1 1 1 1 1
fix 21 1 1 1 1 1 1
fix 23 1 1 1 1 1 1
fix 25 1 1 1 1 1 1
fix 27 1 1 1 1 1 1
fix 29 1 1 1 1 1 1
fix 31 1 1 1 1 1 1


#section ElasticMembranePlateSection $secTag $E $nu $h $rho---------------
section ElasticMembranePlateSection 1 30000 0.2 60 2.3E-9
section ElasticMembranePlateSection 2 30000 0.2 49 2.3E-9

# Definition of elements--------------------------------------------------
# Definition of shell
element ShellMITC4 1 1 2 3 4 1
element ShellMITC4 2 2 5 6 3 1
element ShellMITC4 3 5 7 8 6 1
element ShellMITC4 4 7 9 10 8 1
element ShellMITC4 5 9 11 12 10 1
element ShellMITC4 6 11 13 14 12 1
element ShellMITC4 7 13 15 16 14 1
element ShellMITC4 8 15 17 18 16 1
element ShellMITC4 9 17 19 20 18 1
element ShellMITC4 10 19 21 22 20 1
element ShellMITC4 11 21 23 24 22 1
element ShellMITC4 12 23 25 26 24 1
element ShellMITC4 13 25 27 28 26 1
element ShellMITC4 14 27 29 30 28 1
element ShellMITC4 15 29 31 32 30 1
element ShellMITC4 16 31 1 4 32 1
element ShellMITC4 17 4 3 33 34 1
element ShellMITC4 18 3 6 35 33 1
element ShellMITC4 19 6 8 36 35 1
element ShellMITC4 20 8 10 37 36 1
element ShellMITC4 21 10 12 38 37 1
element ShellMITC4 22 12 14 39 38 1
element ShellMITC4 23 14 16 40 39 1
element ShellMITC4 24 16 18 41 40 1
element ShellMITC4 25 18 20 42 41 1
element ShellMITC4 26 20 22 43 42 1
element ShellMITC4 27 22 24 44 43 1
element ShellMITC4 28 24 26 45 44 1
element ShellMITC4 29 26 28 46 45 1
element ShellMITC4 30 28 30 47 46 1
element ShellMITC4 31 30 32 48 47 1
element ShellMITC4 32 32 4 34 48 1
element ShellMITC4 33 34 33 49 50 1
element ShellMITC4 34 33 35 51 49 1
element ShellMITC4 35 35 36 52 51 1
element ShellMITC4 36 36 37 53 52 1
element ShellMITC4 37 37 38 54 53 1
element ShellMITC4 38 38 39 55 54 1
element ShellMITC4 39 39 40 56 55 1
element ShellMITC4 40 40 41 57 56 1
element ShellMITC4 41 41 42 58 57 1
element ShellMITC4 42 42 43 59 58 1
element ShellMITC4 43 43 44 60 59 1
element ShellMITC4 44 44 45 61 60 1
element ShellMITC4 45 45 46 62 61 1
element ShellMITC4 46 46 47 63 62 1
element ShellMITC4 47 47 48 64 63 1
element ShellMITC4 48 48 34 50 64 1
element ShellMITC4 49 50 49 65 66 1
element ShellMITC4 50 49 51 67 65 1
element ShellMITC4 51 51 52 68 67 1
element ShellMITC4 52 52 53 69 68 1
element ShellMITC4 53 53 54 70 69 1
element ShellMITC4 54 54 55 71 70 1
element ShellMITC4 55 55 56 72 71 1
element ShellMITC4 56 56 57 73 72 1
element ShellMITC4 57 57 58 74 73 1
element ShellMITC4 58 58 59 75 74 1
element ShellMITC4 59 59 60 76 75 1
element ShellMITC4 60 60 61 77 76 1
element ShellMITC4 61 61 62 78 77 1
element ShellMITC4 62 62 63 79 78 1
element ShellMITC4 63 63 64 80 79 1
element ShellMITC4 64 64 50 66 80 1
# Definition of roof
element ShellMITC4 65 66 65 81 82 2
element ShellMITC4 66 65 67 83 81 2
element ShellMITC4 67 67 68 84 83 2
element ShellMITC4 68 68 69 85 84 2
element ShellMITC4 69 69 70 86 85 2
element ShellMITC4 70 70 71 87 86 2
element ShellMITC4 71 71 72 88 87 2
element ShellMITC4 72 72 73 89 88 2
element ShellMITC4 73 73 74 90 89 2
element ShellMITC4 74 74 75 91 90 2
element ShellMITC4 75 75 76 92 91 2
element ShellMITC4 76 76 77 93 92 2
element ShellMITC4 77 77 78 94 93 2
element ShellMITC4 78 78 79 95 94 2
element ShellMITC4 79 79 80 96 95 2
element ShellMITC4 80 80 66 82 96 2
element ShellMITC4 81 82 81 97 98 2
element ShellMITC4 82 81 83 99 97 2
element ShellMITC4 83 83 84 100 99 2
element ShellMITC4 84 84 85 101 100 2
element ShellMITC4 85 85 86 102 101 2
element ShellMITC4 86 86 87 103 102 2
element ShellMITC4 87 87 88 104 103 2
element ShellMITC4 88 88 89 105 104 2
element ShellMITC4 89 89 90 106 105 2
element ShellMITC4 90 90 91 107 106 2
element ShellMITC4 91 91 92 108 107 2
element ShellMITC4 92 92 93 109 108 2
element ShellMITC4 93 93 94 110 109 2
element ShellMITC4 94 94 95 111 110 2
element ShellMITC4 95 95 96 112 111 2
element ShellMITC4 96 96 82 98 112 2
element ShellMITC4 97 98 97 113 114 2
element ShellMITC4 98 97 99 115 113 2
element ShellMITC4 99 99 100 116 115 2
element ShellMITC4 100 100 101 117 116 2
element ShellMITC4 101 101 102 118 117 2
element ShellMITC4 102 102 103 119 118 2
element ShellMITC4 103 103 104 120 119 2
element ShellMITC4 104 104 105 121 120 2
element ShellMITC4 105 105 106 122 121 2
element ShellMITC4 106 106 107 123 122 2
element ShellMITC4 107 107 108 124 123 2
element ShellMITC4 108 108 109 125 124 2
element ShellMITC4 109 109 110 126 125 2
element ShellMITC4 110 110 111 127 126 2
element ShellMITC4 111 111 112 128 127 2
element ShellMITC4 112 112 98 114 128 2

#Eigenvalue analysis----------------------------------------------------------------------------------
set numModes 5
set lambda [eigen $numModes];
# calculate frequencies and periods of the structure
set omega {}
set f {}
set T {}
set pi 3.141593

foreach lam $lambda {
lappend omega [expr sqrt($lam)]
lappend f [expr sqrt($lam)/(2*$pi)]
lappend T [expr (2*$pi)/sqrt($lam)]
}
puts "periods are $T"

# Display of Model3D --------------------------------------------------------------------------------
source DisplayPlane.txt
source DisplayModel3D.txt
set ShapeType DeformedShape;
set dAmp 10; # scaling factor for viewing deformed shape, it depends on the dimensions of the model
set viewPlane XZ;
set nEigen 1;
set quadrant 0;
set xPixels 1200; # height of graphical window in pixels
set yPixels 800; # height of graphical window in pixels
set xLoc1 10; # horizontal location of graphical window (0=upper left-most corner)
set yLoc1 10; # vertical location of graphical window (0=upper left-most corner)
#DisplayPlane $ShapeType $dAmp $viewPlane $nEigen $quadrant
DisplayModel3D $ShapeType $dAmp $xLoc1 $yLoc1 $xPixels $yPixels $nEigen

# Define ground motion--------------------------------------------------------------------------------------
set MotionInterval 0.004
set MotionFile "Elcentro.txt"
set MotionScale 0.01
set MotionStep 1500
set gaccelhorizontal "Series -dt $MotionInterval -filePath $MotionFile -factor $MotionScale"
pattern UniformExcitation 1 1 -accel $gaccelhorizontal

#Create the recorder objects-------------------------------------------------------------------------------
recorder Node -file "top_dsp.txt " -time -node 121 -dof 1 2 3 disp
recorder Node -file "top_vel.txt " -time -node 121 -dof 1 2 3 vel
recorder Node -file "top_acc.txt " -time -node 121 -dof 1 2 3 accel

# Definition of analysis-----------------------------------------------------------------------------------
constraints Plain
numberer RCM
system SparseGeneral
test EnergyIncr 1.0e-6 100
algorithm Newton
integrator Newmark 0.5 0.25
analysis Transient
set Nsteps $MotionStep ;
set ok [analyze $Nsteps $MotionInterval];
if {$ok != 0} {
set ok 0;
set controlTime [getTime];
while {$controlTime < $TmaxAnalysis && $ok == 0} {
set controlTime [getTime]
set ok [analyze 1 $MotionInterval]
if {$ok != 0} {
puts "Trying Newton with Initial Tangent .."
test NormDispIncr $Tol 1000 0
algorithm Newton -initial
set ok [analyze 1 $MotionInterval]
test $testTypeDynamic $TolDynamic $maxNumIterDynamic 0
algorithm $algorithmTypeDynamic
}
if {$ok != 0} {
puts "Trying Broyden .."
algorithm Broyden 8
set ok [analyze 1 $MotionInterval]
algorithm $algorithmTypeDynamic
}
if {$ok != 0} {
puts "Trying NewtonWithLineSearch .."
algorithm NewtonLineSearch .8
set ok [analyze 1 $MotionInterval]
algorithm $algorithmTypeDynamic
}
}
}; # end if ok !0

#---------------------------------------------------------------------------------------------------------------
# Code end
puts "Analysis is done"
exit

[hamidreza]

Hi Wang
Do you still have that problem or could solve it? If you didn't, I can take a look on your model.
Please let me know if you solved it.
Regards,