What's wrong with the quadUP element?

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michaelshu
Posts: 7
Joined: Mon Oct 30, 2006 5:24 am
Location: zhe jiang university

What's wrong with the quadUP element?

Post by michaelshu »

Dear,all users!
I tried to analysize a problem with quadUP element,when I apllied forces on a node, it didn't work.
And gived the warning as :
"WARNING: CTestNormDispIncr::test() - failed to converge
after: 25 iterations
NewtnRaphson::solveCurrentStep() -the ConvergenceTest object failed in test()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 35000
OpenSees > analyze failed, returned: -3 error flag
Execution time: 1 seconds."
What's wrong with the script?Can anyone help me?Many thanks!!

Code: Select all

#SI units (m, s, KN, ton)
#         4    
#         ------- 3
#         |     |
#         |     |
#         |     |
#        1-------2   (nodes 1 and 2 fixed)
#         ^     ^
#          <--> input motion: sinusoidal acceleration at base
wipe
#
#some user defined variables
# 
set matOpt   1      ;# 1 = pressure depend; 
                    ;# 2 = pressure independ; 
set fmass  1      ;# fluid mass density
set smass  2      ;# saturated soil mass density
#: set G     6.e4     ;
#: set B     2.4e5    ;
set G     6.e6    ;
set B     2.4e7    ;
#: set bulk   2.2e6  ;#fluid-solid combined bulk modulus
set bulk   2.2e8  ;#fluid-solid combined bulk modulus
set vperm  5.e-4  ;#vertical permeability (m/s)
set hperm  5.e-4  ;#horizontal permeability (m/s)
set accGravity  9.81    ;#acceleration of gravity
set vperm  [expr $vperm/$accGravity/$fmass]  ;#actual value used in computation
set hperm  [expr $hperm/$accGravity/$fmass]  ;#actual value used in computation
set press   0.    ;# isotropic consolidation pressure on quad element(s)
set loadBias 0.07     ;# Static shear load, in percentage of gravity load (=sin(inclination angle))

set accMul  2.  ;# acc. multiplier
set accNam  whatever.acc  ;# file name for input acc. record 
set accDt   0.0166   ;# dt of input acc. record
set period   1.0      ;# Period for applied Sine wave
set deltaT   0.01    ;# time step for analysis
set numSteps 2400    ;# number of time steps
set gamma    0.6    ;# Newmark integration parameter

set massProportionalDamping   0. ;
set InitStiffnessProportionalDamping 0.002;

#############################################################
# BUILD MODEL
 #:---------
#create the ModelBuilder
model basic -ndm 2 -ndf 3

# define material and properties
switch $matOpt {
  1 {
    nDMaterial PressureDependMultiYield 1 2 $smass $G $B 31.4 .1 80 0.5\
                                        26.5 0.1 .2 5 10 0.015 1.
  }
  2 {
    nDMaterial PressureIndependMultiYield 2 2 1.8 4.e4 2.e5 40 .1
  }
}

#set material to elastic for gravity loading
updateMaterialStage -material $matOpt -stage 0  
set gravY -$accGravity                 ;#calc. gravity
set gravX [expr -$gravY*$loadBias]

#: ---------------------
# define the nodes
node 1   0.0 0.0 
node 2   1.0 0.0 
node 3   1.0 1.0 
node 4   0.0 1.0
#: ------------------
# define the element      thick  material      maTag   press    mDensity   gravity 
 element quadUP  1  1 2 3 4  1.0  $matOpt $bulk $fmass  $hperm  $vperm $gravX $gravY $press 
#: -------------------------------
# fix the base in vertical direction
fix 1 1 1 0
fix 2 1 1 0
fix 3 0 0 1
fix 4 0 0 1
#:
#:-----------------------------------------
#:
equalDOF 3 4 1 2
#:---------------------------------------------
# #############################################################
# GRAVITY APPLICATION (elastic behavior)

# create the SOE, ConstraintHandler, Integrator, Algorithm and Numberer
numberer RCM
system ProfileSPD
test NormDispIncr 1.0e-8 25 0
algorithm Newton
constraints Penalty 1.e18 1.e18
integrator Newmark 1.5  1.  
analysis Transient 

analyze 3 5.e3
#: --------------Apply force!----------------------
 pattern Plain 5 "Linear" {
 # Create nodal loads at nodes 3 & 4
 # nd FX FY MZ 
load 4 0.01 0 0
 }
 numberer RCM
 system ProfileSPD
 test NormDispIncr 1.0e-8 25 0
algorithm Newton -initial 
#: algorithm ModifiedNewton
#:algorithm NewtonLineSearch 0.8
#:  algorithm KrylovNewton
#: algorithm Broyden 8
 constraints Penalty 1.e18 1.e18
 integrator Newmark 1.5  1.  
 analysis Transient 
 
 recorder Node -file disp2.out   -time  -node 3 4 -dof 1 -dT  0.1 disp
 
 
 analyze 3 5.e3
 
# switch material stage from elastic (gravity) to plastic

updateMaterialStage -material $matOpt -stage 1

analyze 5 5.e3
# rezero time
wipeAnalysis
setTime 0.0


#:--------------------------
pattern UniformExcitation  1  1    -accel "Sine 0. 10. $period -factor $accMul"

recorder Node -file disp_t.out   -node 3 4 -dof 1 2 -time -dT 0.1 disp

#analysis options
constraints Penalty 1.e18 1.e18
test NormDispIncr 1.e-5 25 0
numberer RCM
algorithm Newton
system ProfileSPD
#some mass proportional and initial-stiffness proportional damping
integrator Newmark $gamma  [expr pow($gamma+0.5, 2)/4]  \
     $massProportionalDamping 0.0 $InitStiffnessProportionalDamping 0.0
analysis VariableTransient 

#analyze 
set startT [clock seconds]
analyze $numSteps $deltaT [expr $deltaT/100] $deltaT 15
set endT [clock seconds]
puts "Execution time: [expr $endT-$startT] seconds."

wipe  #flush ouput stream
hengine
Posts: 5
Joined: Thu Nov 16, 2006 8:04 pm
Location: ZJU

i have the same problem with you!

Post by hengine »

i have the same problem with you!
Is it a bug with the element quadUP? :roll:
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