Confusion with Stress Output Unit in OpenSees .out files

[duttaANURAG]

Good Evening Community,

I had a confusion with my output unit in my stress.out files. So I am asking my doubt here.

I am working on Static Earth Pressure of Soil Model in which I have considered a 1m x 1m Soil Box of PDMY Loose Sand having phi = 29 degrees subjected to static anaysis.I have provided hinge support on the base of soil model and roller support on its sides. My OpenSees Program is as follows -



wipe

model BasicBuilder -ndm 2 -ndf 2

#--------------------------------------------------------------
# 2. DEFINE SOIL NODES FOR BACKFILL (2 DOF DOMAIN)
#------------------------------------------------------------


node 1 0.000000 0.000000

node 2 1.000000 0.000000

node 3 1.000000 1.000000

node 4 0.000000 1.000000

node 9 0.000000 0.500000

node 10 0.500000 1.000000

node 11 1.000000 0.500000

node 12 0.500000 0.000000

node 19 0.500000 0.500000

puts "Soil Nodes for Backfill have been generated"


#------------------------------------------------------------

# 3. CREATE nDMaterial OBJECT

#--------------------------------------------------------------

#

# nDMaterial OBJECT for BACKFILL

#

nDMaterial PressureDependMultiYield 1 2 1.70 55000.00 150000.00 \

29 0.10 80.00 0.500 29.000 0.21 0.00 0.00 \

10.00 0.02 1.00 30 0.85

puts "nDMaterial for Backfill is Generated"

#------------------------------------------------
# 4. CREATE InitialStateWrapper MATERIAL

#------------------------------------------------

nDMaterial InitialStateAnalysisWrapper 2 1 2

puts "Wrapper Material for Backfill is Generated"

#---------------------------------------------------------
# 5. DEFINE QUAD ELEMENTS FOR SOIL
#------------------------------------------------------------

#

# . QUAD ELEMENTS for Backfill

#

element quad 15 4 9 19 10 1.00 PlaneStrain 2 0.00 1.700000 0.000000 -16.677000

element quad 16 9 1 12 19 1.00 PlaneStrain 2 0.00 1.700000 0.000000 -16.677000

element quad 17 10 19 11 3 1.00 PlaneStrain 2 0.00 1.700000 0.000000 -16.677000

element quad 18 19 12 2 11 1.00 PlaneStrain 2 0.00 1.700000 0.000000 -16.677000

puts "Quad Elements for Backfill are Generated"

#------------------------------------------------

# 5. Fix Left Side of Backfill (Roller Support)

#------------------------------------------------

fix 4 1 0

fix 9 1 0

#------------------------------------------------

# 6. Fix Right Side of Backfill (Roller Support)

#------------------------------------------------

fix 3 1 0

fix 11 1 0


#------------------------------------------------

# 7. Fix Bottom of Backfill (Hinge Support)

#------------------------------------------------

fix 1 1 1

fix 12 1 1

fix 2 1 1

puts "OpenSees Model for Self Weight Analysis of Backfill Soil System Generated ."

#------------------------------------------------

# 9. Create Recorders for Gravity Analysis

#-----------------------------------------------

file mkdir ./GravityAnalysis

# record nodal displacments at left nodes

recorder Node -file GravityAnalysis/displacementBL.out -time -node 4 9 -dof 1 2 disp

recorder Element -file GravityAnalysis/quadEleStressBL.out -time -eleRange 15 18 stress; #Backfill

recorder Element -file GravityAnalysis/quadEleStrainBL.out -time -eleRange 15 18 strain; #Backfill

recorder Element -file GravityAnalysis/quadEleStressBL1.out -time -ele 15 16 stress; #Backfill

recorder Element -file GravityAnalysis/quadEleStrainBL1.out -time -ele 15 16 strain; #Backfill

#------------------------------------------

#Create Gravity Analysis

#------------------------------------------

logFile LOGFILE.txt

constraints Transformation

numberer RCM

system SparseGeneral

test NormDispIncr 1e-05 300 2

algorithm Newton

integrator LoadControl 0.1

analysis Static

InitialStateAnalysis on

updateMaterialStage -material 2 -stage 0; # Linear Elastic Behaviour

set startT [clock seconds]

analyze 10

puts "Elastic Analysis done..."

puts "MaterialBehavior Changed to Plastic"

updateMaterialStage -material 2 -stage 1

analyze 10

#Turn off Initial State Analysis

InitialStateAnalysis off

set endT [clock seconds]

puts "Analysis execution time: [expr $endT-$startT] seconds"

wipe

After analysis, my stress output is as follows -

2 -2.11574 -4.16925 2.08199e-014 -2.11574 -4.16925 6.47524e-015 -2.11574 -4.16925 -3.06172e-015 -2.11574 -4.16925 1.11344e-014 -6.34722 -12.5077 1.04191e-014 -6.34722 -12.5077 6.01599e-015 -6.34722 -12.5077 1.79864e-014 -6.34722 -12.5077 2.23273e-014 -2.11574 -4.16925 8.00949e-015 -2.11574 -4.16925 1.06229e-014 -2.11574 -4.16925 2.00113e-014 -2.11574 -4.16925 1.69496e-014 -6.34722 -12.5077 4.75082e-014 -6.34722 -12.5077 2.47467e-014 -6.34722 -12.5077 1.27764e-014 -6.34722 -12.5078 3.56e-014

Now, my confusion is that on which unit I am getting these values?

Please kindly help me out.

Your kind help will be appreciated a lot.

Thank You.