Bilin Material (Modified Ibarra-Medina-Krawinkler Deteriorat

[mehdikia2519]

hello every body
I defined Bilin- Material in my model and assign it to zero length element . it is worth noted the zero-length elements define truly . but when i start to run , the analyze irrupt at first step . after substituting this material by other material in opensees library the analyze done .
I do not know why ? perhaps you think the material defined incorrectly but it is noted the Bilin- Material in this model define truly

[fmk]

can you post a 1 ele 2 node model in which this error occurs

[mehdikia2519]

Thanks for your attention dear fmk . in the following a simple model ( one bay - one story frame which has zero length element in node 2 ) presented.
# In the name of god
wipe
model BasicBuilder -ndm 2 <-ndf 3>
# Define nodes

node 1 0.0 0.0
node 2 0.0 400.0
node 3 400.0 400.0
node 4 400.0 0.0
node 2001 0.0 400.0

fix 1 1 1 1
fix 4 1 1 1

uniaxialMaterial Elastic 1 400000000

uniaxialMaterial Hardening 2 400000000 4800000 0.05 0.05

uniaxialMaterial ModIMKPeakOriented 3 400000000 1.05 1.05 4800000 4800000 30 30 30 30 1 1 1 1 0.03 0.03 0.03 0.03 0.4 0.4 0.06 0.06 1 1

geomTransf Corotational 1

element elasticBeamColumn 1 1 2 400 2000000 13333.33333 1
element elasticBeamColumn 2 2001 3 400 2000000 13333.33333 1
element elasticBeamColumn 3 3 4 400 2000000 13333.33333 1
element zeroLength 4 2 2001 -mat 3 -dir 6
equalDOF 2 2001 1 2

pattern Plain 1 "Linear" {
load 2 1 0 0
}

constraints Transformation
numberer RCM
system BandGeneral
test EnergyIncr 10e-10 20
algorithm NewtonLineSearch 0.7
integrator DisplacementControl 2 1 0.01
analysis Static
analyze 10
loadConst -time 0.0

[kostast88]

The $My_neg should be a negative number as below:

uniaxialMaterial ModIMKPeakOriented 3 400000000 1.05 1.05 4800000 -4800000 30 30 30 30 1 1 1 1 0.03 0.03 0.03 0.03 0.4 0.4 0.06 0.06 1 1

[mehdikia2519]

thanks a lot dear kostast88