Bond_SP01 Material

[majidzar]

Hi
my model is RC frame with fiber section I use ReinforcingSteel material for steel my units are SI units but when i run my model the following message appear:
warning:for the strain-penetration model: input value in ksi and in
but my model work correctly
what is that error?and please help me if it make any error in response of structure?
this is my materials
uniaxialMaterial Concrete01 $IDcorecolumn [expr -45.*$Mpa] -.0068 [expr -30.*$Mpa] -.02
uniaxialMaterial Concrete01 $IDcovercolumn [expr -30.*$Mpa] -.003 [expr -30.*$Mpa] -.006
uniaxialMaterial Concrete01 $IDcorebeam [expr -30.*$Mpa] -.003 [expr -30.*$Mpa] -.007
uniaxialMaterial Concrete01 $IDcoverbeam [expr -23.*$Mpa] -.002 [expr -23.*$Mpa] -.005
uniaxialMaterial ReinforcingSteel $IDsteel $Fy $Fu $Es $Esh $esh $eult -CMFatigue .1 .4 .2

thanks

[fmk]

i cannot see the error you detail in the SRC code. it could be that the material is written to work in ksi and in only (most materials are unitless, some are not). to be sure show me the actual command: i.e. do a
puts "uniaxialMaterial ReinforcingSteel $IDsteel $Fy $Fu $Es $Esh $esh $eult -CMFatigue .1 .4 .2 "

[majidzar]

sorry I make a mistake this error was for bond slip material
this is my material for zerolength section element that make this error
uniaxialMaterial Bond_SP01 400 50000 0.07 67000 1.7 0.5 0.5
but when I change 50000 to 72 and 67000 to 97 the warning disappear.
what is that error?and please help me if it make any error in response of structure?
this is my materials

[fmk]

looks like the material requires your units to be ksi and in.

the code that causes the warining is:
if ( fy >= 1000 || sy >= 1)
opserr << "WARNING: For the Strain-Penetration Model: input val\
ues in ksi and in." << endln;

the code creates a number of variables that assume the units are ksi and inch. the code will run, but the results may be meaningless! i suggest you play with a small model to see how results differ.

[majidzar]

Thanks Mr.fmk for your suggestion.
I make a small model with the ksi and inch units. but as I change the variables for ((uniaxialMaterial Bond_SP01)) such as Sy , Su and R the result dose not change as I expected so the hysteresis behavior dose not differ as I expected. for example pinching never change when I change pinching factor.
please inform me if the bond slip material dose not show the barslip as good as expected.
I need a material for capturing the effect of bar slip in cap beams because I must compare my model with an experimental model that barslip in cap beam occur.

this is a small model that you suggest me to play : one column with a cap beam

# bridge T-joint
# -----------------
# Units: kips, in.


# Create ModelBuilder (with two dimensions and 2 DOF/node)
model basic -ndm 2 -ndf 3

node 1 -48 0
node 2 -30 0
node 3 -12 0
node 4 0 0
node 5 12 0
node 6 30 0
node 7 48 0
node 8 0 -12
node 9 0 -19
node 10 0 -40.0
node 11 0 -61.5
node 12 0 -84.0
node 13 0 -12

# Fix supports at base of column
# Tag DX DY RZ
fix 12 1 1 1
#equalDOF $rNodeTag $cNodeTag $dof1 $dof2
equalDOF 8 13 2



# Define materials for nonlinear columns
##column Core CONCRETE tag f'c ec0 f'cu ecu
uniaxialMaterial Concrete01 1 -6.38 -0.004 -5.11 -0.014
uniaxialMaterial Concrete01 200 -6.38 -0.004 -5.11 -0.014
##column Cover CONCRETE tag f'c ec0 f'cu ecu
uniaxialMaterial Concrete01 2 -4.56 -0.002 0.0 -0.006
##column stub CONCRETE tag E
uniaxialMaterial Elastic 3 2280

##beam CONCRETE tag f'c ec0 f'cu ecu
uniaxialMaterial Concrete01 4 -5.76 -0.002 0.0 -0.006

## STEEL rebar
##STEEL02 tag $Fy $E $b $R0 $cR1 $cR2 $a1 $a2 $a3 $a4
uniaxialMaterial Steel02 5 65.0 29000 0.02 18.5 0.925 0.15 0.04 1.0 0.04 1.0
uniaxialMaterial Steel02 6 62.8 29000 0.02 18.5 0.925 0.15 0.00 1.0 0.00 1.0
uniaxialMaterial Elastic 7 29000

#uniaxialMaterial StrPen01 $Tag $fy $sy $fu $su $b $R $Cd $db $fc $la
uniaxialMaterial Bond_SP01 400 65 0.02 97.5 .7 0.50 0.7 0.0 1.0 4.35 25.0
#0.0 1.0 4.35 25.0

# Define cross-section for nonlinear column
set colDia 24; # bending in this direction (local and global y)
set cover 1.38;
set bcent 1.81; # [expr $cover+0.197+0.5]
set As 0.60; # Area of no. 7 bar
set R [expr $colDia/2.0]
set Rc [expr $colDia/2.0-$cover]
set Rb [expr $colDia/2.0-$bcent]

section Fiber 1 {
# core concrete fibers
patch circ 1 70 22 0.0 0.0 0.0 $Rc 0.0 360.0
# concrete cover fibers
patch circ 2 70 2 0.0 0.0 $Rc $R 0.0 360.0
# reinforcing fibers
layer circ 5 14 $As 0.0 0.0 $Rb -90.0 244.3
}
section Fiber 2 {
# core concrete fibers
patch circ 3 70 22 0.0 0.0 0.0 $Rc 0.0 360.0
# concrete cover fibers
patch circ 3 70 2 0.0 0.0 $Rc $R 0.0 360.0
# reinforcing fibers
layer circ 5 14 $As 0.0 0.0 $Rb -90.0 244.3
}

section Fiber 5 {
# core concrete fibers
patch circ 200 70 22 0.0 0.0 0.0 $Rc 0.0 360.0
# concrete cover fibers
patch circ 2 70 2 0.0 0.0 $Rc $R 0.0 360.0
# reinforcing fibers
layer circ 400 14 $As 0.0 0.0 $Rb -90.0 244.3
}

# Define cross-section for nonlinear cap beam
set bmw 27; # bending in this direction (local and global y)
set bmh 24; # bending in this direction (local and global y)
set cover 1.38;
set bcent 1.81; # [expr $cover+0.197+0.5]

set aw [expr $bmw/2.0]
set ac [expr $bmw/2.0-$cover]
set ab [expr $bmw/2.0-$bcent]
set bw [expr $bmh/2.0]
set bc [expr $bmh/2.0-$cover]
set bb [expr $bmh/2.0-$bcent]

section Fiber 3 {
# concrete fibers
patch quad 4 48 1 -$bw -$aw $bw -$aw $bw $aw -$bw $aw
# reinforcing fibers
layer straight 6 7 $As -$bb $ab -$bb -$ab
layer straight 6 7 $As $bb $ab $bb -$ab
}

# Define column elements
## Geometry of coloumn elements
geomTransf PDelta 1
geomTransf PDelta 2

# Number of integration points along length of element
set np 5

# Create the columns using displacement controlled beam-column elements
# tag ndI ndJ nsecs secID transfTag
element dispBeamColumn 1 1 2 $np 3 1
element dispBeamColumn 2 2 3 $np 3 1
element dispBeamColumn 3 3 4 $np 3 1
element dispBeamColumn 4 4 5 $np 3 1
element dispBeamColumn 5 5 6 $np 3 1
element dispBeamColumn 6 6 7 $np 3 1
element dispBeamColumn 7 4 8 $np 2 2
element dispBeamColumn 8 13 9 $np 1 2
element dispBeamColumn 9 9 10 $np 1 2
element dispBeamColumn 10 10 11 $np 1 2
element dispBeamColumn 11 11 12 $np 1 2
# zeroLengthSection tag ndI ndJ secID
element zeroLengthSection 12 8 13 5

# Set up and perform analysis
## Create recorders



recorder Node -file DFree123.out -node 12 -dof 1 reaction;
recorder Node -file node4.out -node 4 -dof 1 disp;




set P -90.0
pattern Plain 1 "Constant" {
load 4 0 $P 0
}

# Define analysis parameters
integrator LoadControl 0
system SparseGeneral -piv
test NormDispIncr 1.0e-4 2000
numberer Plain
constraints Plain
algorithm KrylovNewton
analysis Static

# Do one analysis for constant axial load
analyze 1

# Define reference force
pattern Plain 2 "Linear" {
load 1 2 0 0
}

set dU1 0.01
set dU2 -0.010


# Perform the analysis
integrator DisplacementControl 4 1 $dU1
analyze 20
integrator DisplacementControl 4 1 $dU2
analyze 39
integrator DisplacementControl 4 1 $dU1
analyze 39
integrator DisplacementControl 4 1 $dU2
analyze 39
integrator DisplacementControl 4 1 $dU1
analyze 39
integrator DisplacementControl 4 1 $dU2
analyze 39
integrator DisplacementControl 4 1 $dU1
analyze 4
#############################################
integrator DisplacementControl 4 1 $dU1
analyze 41
integrator DisplacementControl 4 1 $dU2
analyze 81
integrator DisplacementControl 4 1 $dU1
analyze 81
integrator DisplacementControl 4 1 $dU2
analyze 81
integrator DisplacementControl 4 1 $dU1
analyze 81
integrator DisplacementControl 4 1 $dU2
analyze 81
integrator DisplacementControl 4 1 $dU1
analyze 40
#############################################
integrator DisplacementControl 4 1 $dU1
analyze 64
integrator DisplacementControl 4 1 $dU2
analyze 123
integrator DisplacementControl 4 1 $dU1
analyze 123
integrator DisplacementControl 4 1 $dU2
analyze 123
integrator DisplacementControl 4 1 $dU1
analyze 123
integrator DisplacementControl 4 1 $dU2
analyze 123
integrator DisplacementControl 4 1 $dU1
analyze 59
#############################################
integrator DisplacementControl 4 1 $dU1
analyze 89
integrator DisplacementControl 4 1 $dU2
analyze 166
integrator DisplacementControl 4 1 $dU1
analyze 166
integrator DisplacementControl 4 1 $dU2
analyze 166
integrator DisplacementControl 4 1 $dU1
analyze 166
integrator DisplacementControl 4 1 $dU2
analyze 166
integrator DisplacementControl 4 1 $dU1
analyze 77
##############################################
integrator DisplacementControl 4 1 $dU1
analyze 105
integrator DisplacementControl 4 1 $dU2
analyze 210
integrator DisplacementControl 4 1 $dU1
analyze 210
integrator DisplacementControl 4 1 $dU2
analyze 210
integrator DisplacementControl 4 1 $dU1
analyze 210
integrator DisplacementControl 4 1 $dU2
analyze 210
integrator DisplacementControl 4 1 $dU1
analyze 105
##############################################
integrator DisplacementControl 4 1 $dU1
analyze 125
integrator DisplacementControl 4 1 $dU2
analyze 250
integrator DisplacementControl 4 1 $dU1
analyze 250
integrator DisplacementControl 4 1 $dU2
analyze 250
integrator DisplacementControl 4 1 $dU1
analyze 250
integrator DisplacementControl 4 1 $dU2
analyze 250
integrator DisplacementControl 4 1 $dU1
analyze 125

#end of cycling loading

[fmk]

i am out of the offoce until the 10'th and can only answer posts that require no running of the interpreter as i only have a working ipad with me. my laptop is sadly dead.

[majidzar]

fmk wrote:
> i am out of the offoce until the 10'th and can only answer posts that
> require no running of the interpreter as i only have a working ipad with
> me. my laptop is sadly dead.


OK thanks I make a bigger model (RC one story frame my original model) in ksi and inch and get good result as i change parameters in bond_sp01
but i am wonder why bond_sp01 material dose not work good in SI units?

[majidzar]

Hi fmk
Can we use R=0.3 in uniaxialMaterial Bond_SP01
this is that I used uniaxialMaterial Bond_SP01 $tag2 $Fy 0.056 $Fu 2.24 0.5 0.3
but Pinching factor for the cyclic slip vs. bar response is between0.5~1.0 but I get good answer with R=0.3
what about Sy? what is alpha for creating Sy?why we must get alpha 0.4 in Sy formula????
thanks

[fmk]

you can use whatever parameters you want for any material .. the documentation merely gives suggestions on a valid range

did you read the paper they reference; alpha and why 0.4 is mentioned in it!
https://pantherfile.uwm.edu/jzhao/www/B ... _JZ_SS.pdf

you can always email Prof. Zhao for some feedback.
http://www4.uwm.edu/ceas/faculty_profiles/JZhao.html

[majidzar]

Hi fmk
how could I found Sy in USA units?