EalsticPPGap material error

[gswarup]

Hi,

I am trying to use the ElasticPPGap material in OpenSees but getting error if I put any numerical value for the gap. If the gap is 0.0 the program is running perfectly. Following is my .tcl script. Please help. Thank you...

wipe
logFile viewlog
model BasicBuilder -ndm 2 -ndf 3

set E0 3.35E+03
set Fy 54.0
set gap 0.01
set b 0.001

uniaxialMaterial ElasticPPGap 1 $E0 $Fy $gap 0.01

section Uniaxial 101 1 P

set axialLoad 1.0; # + Tension, - Compression

# Define two nodes at (0,0)
node 1001 0.0 0.0
node 1002 0.0 0.0

# Fix all degrees of freedom except axial and bending
fix 1001 1 1 1
fix 1002 0 1 1

# Define element
# tag ndI ndJ secTag
element zeroLengthSection 2001 1001 1002 101

# Define constant axial load
pattern Plain 3001 "Linear" {
load 1002 $axialLoad 0.0 0.0
}

recorder Node -file Disp.out -node 1002 -dof 1 disp
recorder Node -file Reac.out -node 1001 -dof 1 reaction

system BandGeneral
test EnergyIncr 1.0e-9 10
algorithm Newton
constraints Transformation
numberer Plain

integrator DisplacementControl 1002 1 0.001
analysis Static
analyze 100

puts "Analysis Finished"

Following is the error statement I am geting,

WARNING BandGenLinLapackSolver::solve() -LAPACK routine returned 1
DisplacementControl::newStep(void) - failed in solver
StaticAnalysis::analyze() - the Integrator failed at iteration: 0 with domain at load factor 0
OpenSees > analyze failed, returned: -2 error flag
Analysis Finished

If I put gap = 0.0 then the program is running fine.