A shell element resting on vertical springs

[CBabakhanians]

Hi All,
The model is a shell element resting on four vertical springs.
A static analysis is desired. but the results are not true for ENT and linear springs
The exact solution is:
# ----------------------------------------
# Exact Results (Displacement, m):
# 1: -1.627
# 2: -4.879
# 3: -1.627
# 4: 1.625
# ----------------------------------------
# Exact Results-Uplift (Displacement, m):
# 1: -0.002
# 2: -6.503
# 3: -0.002
# 4: 6.499
-------------------------------------------------------
Model Definition:


#Units N-m
wipe
model BasicBuilder -ndm 3 -ndf 6

node 1 0.0 0.0 0.0
node 2 0.1524 0.0 0.0
node 3 0.1524 0.1524 0.0
node 4 0.0 0.1524 0.0

node 5 0.0 0.0 0.0
node 6 0.1524 0.0 0.0
node 7 0.1524 0.1524 0.0
node 8 0.0 0.1524 0.0

nDMaterial ElasticIsotropic 1 2.289e10 0.2
nDMaterial PlateFiber 11 1
#section ElasticMembranePlateSection 1 2.289e10 0.2 0.6096 0.
section PlateFiber 1 11 0.6096

uniaxialMaterial Elastic 2 68408.92
uniaxialMaterial ENT 3 1e+25
uniaxialMaterial Series 4 2 3
uniaxialMaterial ENT 5 68408.92
# ShellDKGQ
element ShellMITC4 1 1 2 3 4 1

element zeroLength 2 5 1 -mat 2 -dir 3
element zeroLength 3 6 2 -mat 2 -dir 3
element zeroLength 4 7 3 -mat 2 -dir 3
element zeroLength 5 8 4 -mat 2 -dir 3

fix 5 1 1 1 1 1 1
equalDOF 5 6 1 2 3 4 5 6
equalDOF 5 7 1 2 3 4 5 6
equalDOF 5 8 1 2 3 4 5 6

equalDOF 5 1 1 2 6
equalDOF 5 2 1 2 6
equalDOF 5 3 1 2 6
equalDOF 5 4 1 2 6

eval " timeSeries Path 1 -time { 0.0 1.0 } -values {0.0 1.0 } "
#timeSeries Constant 1
pattern Plain 1 1 {
load 2 0. 0. -4.449e5 0. 0. 0.
}
set TheRoot1 "C:\\Users\\HP\\Desktop\\disppp.txt"

set tagNodeDisp [ recorder Node -file $TheRoot1 -time -nodeRange 1 4 -dof 3 disp ]

constraints Plain
numberer RCM
system FullGeneral; #BandGeneral; #Umfpack FullGeneral
#test NormDispIncr 1e-7 5000
test EnergyIncr 1e-17 50000 ; # 2
#algorithm Linear -initial ; # ; #-initial -factorOnce ; # -initial
algorithm BFGS ;#-initial; # -initial KrylovNewton BFGS Broyden
integrator LoadControl 1.
analysis Static
for {set i 1} {$i <= 1} {incr i} {
analyze 1
#reset
}
remove recorder $tagNodeDisp