An elastic model without deformation.

[Carlota Gama]

Hello,

I need help figuring why a very simple square elastic model under 0.1 g accelerogram shows no deformation at all, i.e. all the nodal points have the same approximate acceleration output record and the relative displacements are smaller that 10e-13m . It's a block with 40x30 (m), Young's modulus of 100000 KPa, poisson coefficient of 0,4 and Rayleigh damping with a 0.001 stiffness proportional damping, with a 0.001 factor.

Below is the input file. I wonder why there is no deformation in this model, did I miss something?

Thank you for the attention.
Regards,

Carlota Gama


_______________________________
wipe
#
file mkdir Data


set accMul 1 ;# acceleration multiplier
set massDen 1.50
set fluidDen 1.0 ;# fluid mass density
set massProportionalDamping 0.0 ;
set stiffnessProportionalDamping 0.001 ;
set E 100000.0 ;#shear modulus
set poisson 0.30 ;
set press 0.0 ;# isotropic consolidation pressure on quad element(s)
set deltaT 0.010 ;# time step for analysis
set numSteps 3600 ;# Number of analysis steps
set gamma 0.500 ;# Newmark integration parameter
set pi 3.1415926535 ;
set inclination 0 ;
set unitWeightX [expr ($massDen-$fluidDen)*9.81*sin($inclination/180.0*$pi)] ;# unit weight in X direction
set unitWeightY [expr -($massDen-$fluidDen)*9.81*cos($inclination/180.0*$pi)] ;# unit weight in Y direction
#############################################################

#############################################################

#create the ModelBuilder
model basic -ndm 2 -ndf 2

# define material and properties
nDMaterial ElasticIsotropic 1 $E $poisson


# define the nodes
node 1 0.000 30.000
node 2 0.000 27.000
node 3 4.000 30.000
node 4 4.000 27.000
node 5 0.000 24.000
node 6 4.000 24.000
node 7 8.000 30.000
node 8 8.000 27.000
node 9 0.000 21.000
node 10 4.000 21.000
node 11 8.000 24.000
node 12 0.000 18.000
node 13 12.000 30.000
node 14 8.000 21.000
node 15 12.000 27.000
node 16 4.000 18.000
node 17 12.000 24.000
node 18 8.000 18.000
node 19 0.000 15.000
node 20 12.000 21.000
node 21 4.000 15.000
node 22 16.000 30.000
node 23 16.000 27.000
node 24 12.000 18.000
node 25 8.000 15.000
node 26 16.000 24.000
node 27 0.000 12.000
node 28 16.000 21.000
node 29 4.000 12.000
node 30 12.000 15.000
node 31 8.000 12.000
node 32 20.000 30.000
node 33 16.000 18.000
node 34 20.000 27.000
node 35 20.000 24.000
node 36 0.000 9.000
node 37 4.000 9.000
node 38 12.000 12.000
node 39 20.000 21.000
node 40 16.000 15.000
node 41 8.000 9.000
node 42 20.000 18.000
node 43 24.000 30.000
node 44 0.000 6.000
node 45 16.000 12.000
node 46 12.000 9.000
node 47 24.000 27.000
node 48 4.000 6.000
node 49 24.000 24.000
node 50 20.000 15.000
node 51 8.000 6.000
node 52 24.000 21.000
node 53 16.000 9.000
node 54 24.000 18.000
node 55 12.000 6.000
node 56 20.000 12.000
node 57 0.000 3.000
node 58 4.000 3.000
node 59 28.000 30.000
node 60 28.000 27.000
node 61 8.000 3.000
node 62 24.000 15.000
node 63 28.000 24.000
node 64 16.000 6.000
node 65 20.000 9.000
node 66 28.000 21.000
node 67 12.000 3.000
node 68 24.000 12.000
node 69 0.000 0.000
node 70 4.000 0.000
node 71 28.000 18.000
node 72 8.000 0.000
node 73 20.000 6.000
node 74 16.000 3.000
node 75 28.000 15.000
node 76 24.000 9.000
node 77 32.000 30.000
node 78 32.000 27.000
node 79 12.000 0.000
node 80 32.000 24.000
node 81 32.000 21.000
node 82 28.000 12.000
node 83 20.000 3.000
node 84 24.000 6.000
node 85 16.000 0.000
node 86 32.000 18.000
node 87 28.000 9.000
node 88 32.000 15.000
node 89 36.000 30.000
node 90 20.000 0.000
node 91 24.000 3.000
node 92 36.000 27.000
node 93 36.000 24.000
node 94 32.000 12.000
node 95 28.000 6.000
node 96 36.000 21.000
node 97 36.000 18.000
node 98 32.000 9.000
node 99 24.000 0.000
node 100 28.000 3.000
node 101 36.000 15.000
node 102 40.000 30.000
node 103 32.000 6.000
node 104 40.000 27.000
node 105 36.000 12.000
node 106 40.000 24.000
node 107 40.000 21.000
node 108 28.000 0.000
node 109 36.000 9.000
node 110 40.000 18.000
node 111 32.000 3.000
node 112 40.000 15.000
node 113 36.000 6.000
node 114 40.000 12.000
node 115 32.000 0.000
node 116 36.000 3.000
node 117 40.000 9.000
node 118 40.000 6.000
node 119 36.000 0.000
node 120 40.000 3.000
node 121 40.000 0.000



# define the element thick material maTag press density gravity
element quad 1 2 4 3 1 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 2 5 6 4 2 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 3 9 10 6 5 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 4 12 16 10 9 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 5 19 21 16 12 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 6 27 29 21 19 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 7 36 37 29 27 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 8 44 48 37 36 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 9 57 58 48 44 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 10 69 70 58 57 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 11 4 8 7 3 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 12 6 11 8 4 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 13 10 14 11 6 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 14 16 18 14 10 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 15 21 25 18 16 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 16 29 31 25 21 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 17 37 41 31 29 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 18 48 51 41 37 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 19 58 61 51 48 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 20 70 72 61 58 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 21 8 15 13 7 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 22 11 17 15 8 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 23 14 20 17 11 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 24 18 24 20 14 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 25 25 30 24 18 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 26 31 38 30 25 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 27 41 46 38 31 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 28 51 55 46 41 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 29 61 67 55 51 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 30 72 79 67 61 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 31 15 23 22 13 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 32 17 26 23 15 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 33 20 28 26 17 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 34 24 33 28 20 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 35 30 40 33 24 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 36 38 45 40 30 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 37 46 53 45 38 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 38 55 64 53 46 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 39 67 74 64 55 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 40 79 85 74 67 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 41 23 34 32 22 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 42 26 35 34 23 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 43 28 39 35 26 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 44 33 42 39 28 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 45 40 50 42 33 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 46 45 56 50 40 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 47 53 65 56 45 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 48 64 73 65 53 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 49 74 83 73 64 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 50 85 90 83 74 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 51 34 47 43 32 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 52 35 49 47 34 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 53 39 52 49 35 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 54 42 54 52 39 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 55 50 62 54 42 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 56 56 68 62 50 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 57 65 76 68 56 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 58 73 84 76 65 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 59 83 91 84 73 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 60 90 99 91 83 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 61 47 60 59 43 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 62 49 63 60 47 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 63 52 66 63 49 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 64 54 71 66 52 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 65 62 75 71 54 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 66 68 82 75 62 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 67 76 87 82 68 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 68 84 95 87 76 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 69 91 100 95 84 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 70 99 108 100 91 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 71 60 78 77 59 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 72 63 80 78 60 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 73 66 81 80 63 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 74 71 86 81 66 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 75 75 88 86 71 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 76 82 94 88 75 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 77 87 98 94 82 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 78 95 103 98 87 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 79 100 111 103 95 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 80 108 115 111 100 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 81 78 92 89 77 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 82 80 93 92 78 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 83 81 96 93 80 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 84 86 97 96 81 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 85 88 101 97 86 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 86 94 105 101 88 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 87 98 109 105 94 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 88 103 113 109 98 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 89 111 116 113 103 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 90 115 119 116 111 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 91 92 104 102 89 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 92 93 106 104 92 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 93 96 107 106 93 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 94 97 110 107 96 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 95 101 112 110 97 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 96 105 114 112 101 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 97 109 117 114 105 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 98 113 118 117 109 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 99 116 120 118 113 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY
element quad 100 119 121 120 116 1 PlaneStrain 1 $press 0.0 $unitWeightX $unitWeightY



# fix the base
fix 69 1 1
fix 70 1 1
fix 72 1 1
fix 79 1 1
fix 85 1 1
fix 90 1 1
fix 99 1 1
fix 108 1 1
fix 115 1 1
fix 119 1 1
fix 121 1 1


#Boundary Conditions
equalDOF 1 102 1 2
equalDOF 2 104 1 2
equalDOF 5 106 1 2
equalDOF 9 107 1 2
equalDOF 12 110 1 2
equalDOF 19 112 1 2
equalDOF 27 114 1 2
equalDOF 36 117 1 2
equalDOF 44 118 1 2
equalDOF 57 120 1 2

puts "Modelo construído."

#############################################################
# GRAVITY APPLICATION (elastic behavior)
# create the SOE, ConstraintHandler, Integrator, Algorithm and Numberer
system ProfileSPD
test NormDispIncr 1.e-12 25 0
constraints Transformation
integrator LoadControl 1 1 1 1
algorithm Newton
numberer RCM

# create the Analysis
analysis Static

#analyze
analyze 2

puts "Gravidade aplicada."
############################################################
# NOW APPLY LOADING SEQUENCE AND ANALYZE

# rezero time
setTime 0.0

wipeAnalysis

set GM "Series -dt 0.02 -filePath acelerograma.txt -factor $accMul"

pattern UniformExcitation 1 1 -accel $GM


# create the Analysis
constraints Transformation;
test NormDispIncr 1.e-6 25 0
algorithm Newton
numberer RCM
system ProfileSPD
rayleigh $massProportionalDamping 0.0 $stiffnessProportionalDamping 0.
integrator Newmark $gamma [expr pow($gamma+0.5, 2)/4]
analysis VariableTransient

recorder Node -file Data/disp.txt -time -node 90 83 73 65 56 50 42 39 35 34 32 19 112 1 102 -dof 1 -dT 0.01 disp
recorder Node -file Data/acce.txt -time -node 90 83 73 65 56 50 42 39 35 34 32 19 112 1 102 -dof 1 -dT 0.01 accel

recorder Element -ele 56 -time -file Data/stress56_1.txt -dT 0.01 material 1 stress
recorder Element -ele 56 -time -file Data/strain56_1.txt -dT 0.01 material 1 strain
recorder Element -ele 56 -time -file Data/stress56_3.txt -dT 0.01 material 3 stress
recorder Element -ele 56 -time -file Data/strain56_3.txt -dT 0.01 material 3 strain

#analyze
set startT [clock seconds]
analyze $numSteps $deltaT [expr $deltaT/100] $deltaT 10
set endT [clock seconds]
puts "Execution time: [expr $endT-$startT] seconds."

wipe #flush ouput stream

[pozyczki]

long log

[fmk]

you have provided no mass .. either specify a rho in the material or something for the element.