Error using "nDMaterial FAReinforcedConcretePlaneStress"

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Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby polimeruvijay » Mon May 28, 2018 5:36 am

Dear OpenSees Community Members

I am using "nDMaterial FAReinforcedConcretePlaneStress" for modelling a framed shear wall, I used nonlinear beam column elements to model the beams and columns and used "nDMaterial FAReinforcedConcretePlaneStress" for modelling wall elements. Joined the common nodes of beam, columns and plane stress elements using EqualDOF command. I subjected the sehar wall to cyclic loading.

My problem is: Upto certain displacement cycles, analysis is working good but after that the norm value is becoming higher and higher, no convergence at all in the load-displacement plots. values of load-displacement looks like garbage values.

I as have attached the "nDMaterial FAReinforcedConcretePlaneStress" definition as below.

# set fc fy E
set wfc 32.2;
set wfyv 418;
set wfyh1 420.0;
set wE 200000.0;
set rouv 0.016;
set rouh1 0.002;
set rou1 0.0
set rou2 0.0
set eps_c 0.003

# UniaxialMaterial: steelZ01
# tag fy E0 fpc rou
uniaxialMaterial SteelZ01 11 $wfyv $wE $wfc $rouv
uniaxialMaterial SteelZ01 12 $wfyh1 $wE $wfc $rouh1


# UniaxialMaterial: concreteZ01
# ConcreteZ01 tag f'c ec0
uniaxialMaterial ConcreteZ01 14 [expr -$wfc] [expr -$eps_c]
uniaxialMaterial ConcreteZ01 15 [expr -$wfc] [expr -$eps_c]


set pi 3.14

nDMaterial FAReinforcedConcretePlaneStress 21 0.0 11 12 14 15 [expr 0.0*$pi] [expr 0.5*$pi] $rouv $rouh1 $wfc $wfyv $wE 0.003

Output values as shown below:

-1225.24 -5.29974
-1234.79 -5.39974
-1244.36 -5.49974
-1254.12 -5.59974
-1263.61 -5.69973
-1273.12 -5.79973
-1282.58 -5.89973
-1291.93 -5.99973
-1301.17 -6.09973 ## Upto here values are fine, after that garbage values came into picture, could any one please tell me where might be the wrong
-2543.54 -6.17473
442.817 -6.2978
33.3545 -6.40911
-782.957 -6.50552
4723.83 -6.68576
2381.25 -6.70998
2526.14 -6.79284
-2032.36 -7.123
polimeruvijay
 
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Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby selimgunay » Wed May 30, 2018 7:53 pm

It looks like you should set the convergence tolerances to smaller values to force the analysis to converge and use adaptive solution strategies
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Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby polimeruvijay » Fri Jun 01, 2018 2:11 am

Dear Selim Gunay

Right now I am using a tolerance of 0.01 (NormDispIncr) and KrylovNewton Algorithm for analysis. Could you please suggest any other algorithms which can help solving the error.

Thank you
Vijay
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Posts: 21
Joined: Fri Jan 29, 2016 10:20 pm

Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby fmk » Tue Jun 19, 2018 3:24 am

these materials cause problems .. i have some newer materials for modeling walls .. you might even try forgetting the beam elements with these .. here is some code copied from an example put together by Dr. Petrone

# Concrete
# Parameters for the new concrete model
set E [expr 36900e6*$Pa] ;#elastic modulus
set nu 0.2 ;#Poisson ratio
set fc [expr 56.0e6*$Pa] ;#compressive yield strength
set ft [expr 5.0e6*$Pa] ;#tensile yield strength
set Ap 0.1 ;#damage material data
set An 1.5 ;#damage material data
set Bn 0.75 ;#damage material data
set Beta 0.4

nDMaterial PlasticDamageConcretePlaneStress 10 $E $nu $ft $fc $Beta $Ap $An $Bn; #Boundaries
nDMaterial PlasticDamageConcretePlaneStress 11 $E $nu $ft $fc $Beta $Ap $An $Bn; #Web

#NONLINEAR BIDIRECTIONAL Steel
# STEEL
set Steel 2
set Fy [expr 457.5e+6*$Pa]
set E [expr 200000e+6*$Pa]
set b 0.011042
set R0 20.0
set CR1 0.925
set CR2 0.15
set a1 0.0
set a2 55.0
set a3 0.0
set a4 55.0
#uniaxialMaterial Steel02 $Steel $Fy $E $b $R0 $CR1 $CR2 $a1 $a2 $a3 $a4

#uniaxialMaterial Steel4 $Steel $Fy $E -kin $b 20 0.9 0.15
#uniaxialMaterial Steel02 $Steel $Fy $E $b $R0 $CR1 $CR2 $a1 $a2 $a3 $a4
uniaxialMaterial Steel01 $Steel $Fy $E $b $a1 $a2 $a3 $a4


nDMaterial PlaneStressRebarMaterial 12 $Steel 0; #vertical
nDMaterial PlaneStressRebarMaterial 13 $Steel 90; #horizontal

# define SECTION
set t [expr 6.*2.54*0.01]; #in m

nDMaterial PlaneStressLayeredMaterial 1 3 10 $t 12 [expr $t*.0278] 13 [expr $t*.0278];# Boundaries
nDMaterial PlaneStressLayeredMaterial 2 3 11 $t 12 [expr $t*.00367*1.0] 13 [expr $t*.00367*1.0];#Web FACTOR 1.3


for {set j 0} {$j < $numX} {incr j 1} {
if {$j < $numEdge || $j >= [expr $numX-$numEdge]} {
element quad $eleTag $iNode $jNode $kNode $lNode 1.0 PlaneStress 1
} else {
element quad $eleTag $iNode $jNode $kNode $lNode 1.0 PlaneStress 2
}
fmk
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Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby polimeruvijay » Wed Jul 11, 2018 8:34 pm

Dear FMK

Thank you very much. It seems, "PlasticDamageConcretePlaneStress " and "PlaneStressLayeredMaterial " are available in the latest revisions. I downloaded the source codes. I will update the status on the new materials soon.

Could you please send the download details of Dr. Petrone's Input files and corresponding thesis/research papers for understanding the formulation details.

Thank you
polimeruvijay
 
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Joined: Fri Jan 29, 2016 10:20 pm

Re: Error using "nDMaterial FAReinforcedConcretePlaneStress"

Postby joshwoods » Tue Jul 17, 2018 10:07 pm

Hi Dr. McKenna,

I'm experimenting with this material as well for modelling walls... if there's any information about the "damage material data" parameters from the sample code you posted it would be very useful!

From code:
set Ap 0.1 ;#damage material data
set An 1.5 ;#damage material data
set Bn 0.75 ;#damage material data
set Beta 0.4

Thanks in advance,

Josh
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