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Hi dear all
I have a 2d moment-resistant model with brace. braces are modeled using truss element, columns are nonlinearBeamColumn and beams are elasticBeamColumn. but I got this error after eigen analysis with large period. so what is the problem:
ProfileSPDLinDirectSolver::solve() - aii < 0 (i, aii): (2, 0)

regards

would you please explain more about adding line?

many thanks dear fmk

Hi
I want to apply a displacement history from a file to a pre-defined node. how it is Possible?

Regards

Dear asefsaeedi
you can use this setup file and it works:
download link:
http://opensees.ir/post/76

Thanks for your reply
I just want to capture damage that occurs from fatigue behavior. is that important to record stress and strain of the material?

Regards

Hi dear all
I have a nonlinear model with reinforced concrete fiber section with fatigue material as below:
set Fy 235344000.0;
set E 199934720314.0;
set b 0.03;
set R0 15.0;
set cR1 0.925;
set cR2 0.15;
set a1 0;
set a2 1;
set a3 0;
set a4 1;
uniaxialMaterial Steel02 11 $Fy $E $b $R0 $cR1 $cR2 $a1 $a2 $a3 $a4

uniaxialMaterial Fatigue 111 11

uniaxialMaterial Concrete02 22 -22.05E6 -0.00219 -12.815E6 -0.00759 0.15 2.855E6 1427.5E6 ;

uniaxialMaterial Fatigue 222 22

section Fiber 1 { ;
# Core
patch circ 222 20 10 0.0 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
# Cover
patch circ 222 20 3 0.0 0.0 [expr ($D/2.)-$cover] [expr $D/2.] 0.0 360.
# Bars
layer circ 111 $Nbar [expr pow($Dbar,2.0)*$pi/4.] 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
} ;
.
.
.
element dispBeamColumn 1 1 2 10 1 1 -mass $Mcolumn;
.
.
recorder Element -file DamageSteel.txt -time -ele 1 section 1 material 11 damage
recorder Element -file DamageConc.txt -time -ele 1 section 1 material 22 damage
.
.

after cyclic analysis values of the damage are very small!! is this recorders true for damage? or it should be multiply to something else (such as number of fibers) for making damage index?

regards

thanks dear fmk
Iv run that model. you see damage is near 1 as shown in the example figure. but for my model values are very small. what do you mean by damage index in the fatigue material? how should I define it?
Best

Hi Dear All
I am using fatigue material to make a reinforced concrete fiber section. when I record damage of the element, values of the damage are very small such as 2.e-9. what is the problem. in the same studies damage is between 0 to 1. should I multiply this damage to something else? my recorder is as follow:
.
.
uniaxialMaterial Steel01 1 $Fy $E $b
uniaxialMaterial Fatigue 81 1

uniaxialMaterial Concrete02 2 -21E6 -0.00175 0.0 -0.004 0.15 2.855E6 1427.5E6 ;
uniaxialMaterial Fatigue 82 2
.
.
section Fiber 1 { ;
# Core
patch circ 82 20 10 0.0 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
# Cover
patch circ 82 20 3 0.0 0.0 [expr ($D/2.)-$cover] [expr $D/2.] 0.0 360.
# Bars
layer circ 81 $Nbar [expr pow($Dbar,2.0)*$pi/4.] 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
} ;
.
.
.
element dispBeamColumn 1 1 2 10 1 1 -mass $Mcolumn;
.
.
TH Analysis . . .
.
.
recorder Element -file Damage_Conc.txt -ele 1 section 1 material 2 damage
recorder Element -file Damage_Steel.txt -ele 1 section 1 material 1 damage


help me!

Regards

Many thanks dear FMK
please explain more. what is the exact right recorder ? when I use fiber in the recorder I should not use material argument?

uniaxialMaterial Steel01 1 $Fy $E $b
uniaxialMaterial Fatigue $IDreinf 1

section Fiber 1 { ;
# Core
patch circ $IDconcC 20 10 0.0 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
# Cover
patch circ $IDconcU 20 3 0.0 0.0 [expr ($D/2.)-$cover] [expr $D/2.] 0.0 360.
# Bars
layer circ $IDreinf $Nbar [expr pow($Dbar,2.0)*$pi/4.] 0.0 0.0 [expr ($D/2.)-$cover] 0.0 360.
} ;



Best

Thanks for your reply
when i have -time option I can see time in the output file but there is no damage in the file!
but when section is just made by one material (steel02) output file has to columns. one for time and another for damage. and when section is composite i have just time in the recorded file.
so what is the problem?
Regards

Hi dear all
I want to record damage in a column that is modeled by dispbeamcolumn element and fiber section. when section is Homogeneous (such as steel) I can monitor damage, but when section is composite (steel and concrete) and I apply fatigue material to bars, I can not record damage!!
how can i record damage of bars in the composite section. I also use fiber argument in the recorder but there is nothing except time in the recorded file. Help me..

uniaxialMaterial Steel01 1 $Fy $E $b

uniaxialMaterial Fatigue 111 1

recorder Element -file Damage.txt -time -ele 1 section 1 fiber 0.0 0.6 material 1 damage


Regards

Hi dear all
I have a moment resistant braced steel frame. I used dispbeamcolumn element for braces and there are couple of nodes at each end of brace elements with equalDOF command to neglect end moments. when I draw push over curve there is a break at the beginning of the curve! what is the problem of this model.

Regards

Hi Dear all
I have a braced frame model. I want to record longitudinal deformation of oblique braces directly. How can I do this? which recorders will be help full?

Regards

Hi dear all
I have modeled a 2D steel frame with piles, during TH analysis I got this error. what does it mean?

UMD2FA: matrix is singular. Only 1068 pivots found.
WARNING UmfpackGenLinSolver::solve(void)- 4 returned in factorization UMD2FA()
WARNING NewtonRaphson::solveCurrentStep() -the LinearSysOfEqn failed in solve()
DirectIntegrationAnalysis::analyze() - the Algorithm failed at time 0.005
OpenSees > analyze failed, returned: -3 error flag

Time History Analysis Finished!

Regards