HELP:nonlinbeamcolumn element recorder

[mpaksoy]

Dear Vesna and All,

I am confused about the recorder:
recorder Element -xml PierforcesSec1.out -time -eleRange 1 10 section 1 force
recorder Element -xml PierforcesSec1.out -time -eleRange 1 10 section 1 force
In 3D, it gives, P MZ MY T VY VZ.

When I check the results for integration points at top and bottom after a pushover in transverse direction, I expect the transverse shear at the top and bottom of the element to have opposite signs as (+) (-).
However, they have the same sign. It doesnt make sense to me. Would you give me a hand please. Thank you.

Murathan

[vesna]

Sectional forces have its on sign convention (e.g., compresion force (-) and tension (+)). Thus, I would expect the shear force to have the same sign for both sections. However, if you record elment forces the sign of a shear force has to be oposite at the top and the bottom of your element as it follows the sign convention of a global coordinate system.

[mairead]

Hi,

I am trying to use the force recorder to find the shear forces in a section but it is only outputting 4 columns which are P Mx My T. How did you get an output with Vx and Vy also?

Thanks very much

Kind regards

Mairead

[vesna]

To get Vx and Vy at the section you need to add shear force - shear deformation relationship to your sections. After you define material representing shear force - shear deformation relationship, use "section Aggregator" command (http://opensees.berkeley.edu/wiki/index ... Aggregator) to add it to previously defined section.

[mairead]

Thanks I did that and I am now getting my shear forces to be zero. Any idea what might be wrong? I have copied and pasted the relevent parts of my code. Thanks very much for your time!

#=========================================================================================
# ELASTIC MATERIAL PROPERTIES
#=========================================================================================

#MATERIAL PROPERTIES
set Ec 30.e9; #Elastic modulus in N/m^2
set v .2; #Poissons Ratio
set Gc [expr $Ec/(2.*(1+$v))]; #Modulus of Rigidity in N/m^2

#=========================================================================================
# DECK MATERIAL PROPERTIES
#=========================================================================================
#UNCONFINED CONCRETE
set Eco [expr 5000000.*pow($fco,.5)]; #Elastic modulus in N/m^2

#STEEL REINFORCEMENT
set Es 200000000000.; #modulus of steel N/m^2
set esu .12; #Longitudinal steel maximum strain
set fsu [expr 1.5*$fy]; #Longitudinal steel ultimate stress N/m^2

#MATERIAL GENERATION
set ConcDeckID 1;
set SteelDeckID 2;
set TorsionDeckID 3;
set ShearDeckID 4;


#Cover concrete (un-confined)
uniaxialMaterial Concrete01 $ConcDeckID [expr -$fco] [expr -(2.0*$fco/$Eco)] -10. -0.00550;

#REINFORCING STEEL Tag fy E b
uniaxialMaterial Steel01 $SteelDeckID $fyh $Es 0.018;

uniaxialMaterial Elastic $TorsionDeckID 1.e10;
#SHEAR MODULUS
uniaxialMaterial Elastic $ShearDeckID $Gc;

#=========================================================================================
# DECK & DIAPHRAGM SECTION PROPERTIES
#=========================================================================================

set SecTagDeckCentreSpan_2D 1;
set SecTagDeckCentreSpan_3D 2;

set SecTagDeckSideSpan_2D 3;
set SecTagDeckSideSpan_3D 4;

set Dtot 1.7;
set Yc .956;
set Dslab .2;
set Bslab 10.;
set Bbot 7.89;
set D 1.5;
set d .3;
set B .97;
set b .17;
set shift 1.73;
set DstrandDeck .0157;
set DBarSlab .02;
set AstrandDeck [expr (3.14*pow($DstrandDeck,2))/4];
set ABarSlab [expr (3.14*pow($DBarSlab,2))/4];
set StrDistDeck .05;



source BuildRCDeckSectionCentreSpan.tcl;
BuildRCDeckSectionCentreSpan $SecTagDeckCentreSpan_2D $Yc $Dtot $Dslab $Bslab $D $d $B $b $shift $ConcDeckID $SteelDeckID $DstrandDeck $AstrandDeck $DBarSlab $ABarSlab $StrDistDeck $cover
section Aggregator $SecTagDeckCentreSpan_3D $TorsionDeckID T $ShearDeckID Vy $ShearDeckID Vz -section $SecTagDeckCentreSpan_2D;

source BuildRCDeckSectionSideSpan.tcl;
BuildRCDeckSectionSideSpan $SecTagDeckSideSpan_2D $Yc $Dtot $Dslab $Bslab $D $d $B $b $shift $ConcDeckID $SteelDeckID $DstrandDeck $AstrandDeck $DBarSlab $ABarSlab $StrDistDeck $cover
section Aggregator $SecTagDeckSideSpan_3D $TorsionDeckID T $ShearDeckID Vy $ShearDeckID Vz -section $SecTagDeckSideSpan_2D;

[vesna]

What is the type of section to which you aggregate shear and torsion?

Try to define your aggregate section by defining shear and torsion in the following order: Vy, Vz, and T.

[mairead]

I tried defining my section in that order but I am still getting zeros for the shear. It is a bridge deck section consisting of a concrete slab with 5 U-beams. I don't think there is a problem with my section however as I used the same section in a simple model fully fixed at both ends and the shears were coming out fine. The problem only arises when I use the section in my bridge model. I have pasted the procedure below which defines my section anyway. Thanks so much for your time.

proc BuildRCDeckSectionCentreSpan {id Yc Dtot Dslab Bslab D d B b shift IDcoverConc IDSteel DStrand Astrand DBarSlab ABarSlab StrDist cover} {

#FIBER SECTION COORDINATES
#Flange Number 1
set F1_Y1 -$Yc;
set F1_Z1 [expr ((2*$shift)+($B/2))];
set F1_Y2 -$Yc;
set F1_Z2 [expr ((2*$shift)-($B/2))];
set F1_Y3 [expr -($Yc-$d)];
set F1_Z3 [expr ((2*$shift)-($B/2))];
set F1_Y4 [expr -($Yc-$d)];
set F1_Z4 [expr ((2*$shift)+($B/2))];

#Flange Number 2
set F2_Y1 -$Yc;
set F2_Z1 [expr ($shift+($B/2))];
set F2_Y2 -$Yc;
set F2_Z2 [expr ($shift-($B/2))];
set F2_Y3 [expr -($Yc-$d)];
set F2_Z3 [expr ($shift-($B/2))];
set F2_Y4 [expr -($Yc-$d)];
set F2_Z4 [expr ($shift+($B/2))];

#Flange Number 3
set F3_Y1 -$Yc;
set F3_Z1 [expr $B/2];
set F3_Y2 -$Yc;
set F3_Z2 [expr -$B/2];
set F3_Y3 [expr -($Yc-$d)];
set F3_Z3 [expr -$B/2];
set F3_Y4 [expr -($Yc-$d)];
set F3_Z4 [expr $B/2];

#Flange Number 4
set F4_Y1 -$Yc;
set F4_Z1 [expr -($shift-($B/2))];
set F4_Y2 -$Yc;
set F4_Z2 [expr -($shift+($B/2))];
set F4_Y3 [expr -($Yc-$d)];
set F4_Z3 [expr -($shift+($B/2))];
set F4_Y4 [expr -($Yc-$d)];
set F4_Z4 [expr -($shift-($B/2))];

#Flange Number 5
set F5_Y1 -$Yc;
set F5_Z1 [expr -((2*$shift)-($B/2))];
set F5_Y2 -$Yc;
set F5_Z2 [expr -((2*$shift)+($B/2))];
set F5_Y3 [expr -($Yc-$d)];
set F5_Z3 [expr -((2*$shift)+($B/2))];
set F5_Y4 [expr -($Yc-$d)];
set F5_Z4 [expr -((2*$shift)-($B/2))];

#Girder 1: Web Number 1
set W1_Y1 [expr -($Yc-$d)];
set W1_Z1 [expr ((2*$shift)+($B/2))];
set W1_Y2 [expr -($Yc-$d)];
set W1_Z2 [expr ((2*$shift)+(($B/2)-$b))];
set W1_Y3 [expr $D-$Yc];
set W1_Z3 [expr ((2*$shift)+(($B/2)-$b))];
set W1_Y4 [expr $D-$Yc];
set W1_Z4 [expr ((2*$shift)+($B/2))];

#Girder 1: Web Number 2
set W2_Y1 [expr -($Yc-$d)];
set W2_Z1 [expr ((2*$shift)-(($B/2)-$b))];
set W2_Y2 [expr -($Yc-$d)];
set W2_Z2 [expr ((2*$shift)-($B/2))];
set W2_Y3 [expr $D-$Yc];
set W2_Z3 [expr ((2*$shift)-($B/2))];
set W2_Y4 [expr $D-$Yc];
set W2_Z4 [expr ((2*$shift)-(($B/2)-$b))];

#Girder 2: Web Number 3
set W3_Y1 [expr -($Yc-$d)];
set W3_Z1 [expr ($shift+($B/2))];
set W3_Y2 [expr -($Yc-$d)];
set W3_Z2 [expr ($shift+(($B/2)-$b))];
set W3_Y3 [expr $D-$Yc];
set W3_Z3 [expr ($shift+(($B/2)-$b))];
set W3_Y4 [expr $D-$Yc];
set W3_Z4 [expr ($shift+($B/2))];

#Girder 2: Web Number 4
set W4_Y1 [expr -($Yc-$d)];
set W4_Z1 [expr ($shift-(($B/2)-$b))];
set W4_Y2 [expr -($Yc-$d)];
set W4_Z2 [expr ($shift-($B/2))];
set W4_Y3 [expr $D-$Yc];
set W4_Z3 [expr ($shift-($B/2))];
set W4_Y4 [expr $D-$Yc];
set W4_Z4 [expr ($shift-(($B/2)-$b))];

#Girder 3: Web Number 5
set W5_Y1 [expr -($Yc-$d)];
set W5_Z1 [expr ($B/2)];
set W5_Y2 [expr -($Yc-$d)];
set W5_Z2 [expr (($B/2)-$b)];
set W5_Y3 [expr $D-$Yc];
set W5_Z3 [expr (($B/2)-$b)];
set W5_Y4 [expr $D-$Yc];
set W5_Z4 [expr ($B/2)];

#Girder 3: Web Number 6
set W6_Y1 [expr -($Yc-$d)];
set W6_Z1 [expr -(($B/2)-$b)];
set W6_Y2 [expr -($Yc-$d)];
set W6_Z2 [expr -($B/2)];
set W6_Y3 [expr $D-$Yc];
set W6_Z3 [expr -($B/2)];
set W6_Y4 [expr $D-$Yc];
set W6_Z4 [expr -(($B/2)-$b)];

#Girder 4: Web Number 7
set W7_Y1 [expr -($Yc-$d)];
set W7_Z1 [expr -($shift-($B/2))];
set W7_Y2 [expr -($Yc-$d)];
set W7_Z2 [expr -($shift-(($B/2)-$b))];
set W7_Y3 [expr $D-$Yc];
set W7_Z3 [expr -($shift-(($B/2)-$b))];
set W7_Y4 [expr $D-$Yc];
set W7_Z4 [expr -($shift-($B/2))];

#Girder 4: Web Number 8
set W8_Y1 [expr -($Yc-$d)];
set W8_Z1 [expr -($shift+(($B/2)-$b))];
set W8_Y2 [expr -($Yc-$d)];
set W8_Z2 [expr -($shift+($B/2))];
set W8_Y3 [expr $D-$Yc];
set W8_Z3 [expr -($shift+($B/2))];
set W8_Y4 [expr $D-$Yc];
set W8_Z4 [expr -($shift+(($B/2)-$b))];

#Girder 5: Web Number 9
set W9_Y1 [expr -($Yc-$d)];
set W9_Z1 [expr -((2*$shift)-($B/2))];
set W9_Y2 [expr -($Yc-$d)];
set W9_Z2 [expr -((2*$shift)-(($B/2)-$b))];
set W9_Y3 [expr $D-$Yc];
set W9_Z3 [expr -((2*$shift)-(($B/2)-$b))];
set W9_Y4 [expr $D-$Yc];
set W9_Z4 [expr -((2*$shift)-($B/2))];

#Girder 5: Web Number 10
set W10_Y1 [expr -($Yc-$d)];
set W10_Z1 [expr -((2*$shift)+(($B/2)-$b))];
set W10_Y2 [expr -($Yc-$d)];
set W10_Z2 [expr -((2*$shift)+($B/2))];
set W10_Y3 [expr $D-$Yc];
set W10_Z3 [expr -((2*$shift)+($B/2))];
set W10_Y4 [expr $D-$Yc];
set W10_Z4 [expr -((2*$shift)+(($B/2)-$b))];

#Slab
set S_Y1 [expr $D-$Yc];
set S_Z1 [expr $Bslab/2];
set S_Y2 [expr $D-$Yc];
set S_Z2 [expr -($Bslab/2)];
set S_Y3 [expr $Dtot-$Yc];
set S_Z3 [expr -($Bslab/2)];
set S_Y4 [expr $Dtot-$Yc];
set S_Z4 [expr $Bslab/2];

#REINFORCING STEEL COORDINATES

#FLANGE NUMBER 1
set RS1_Y1strt [expr -($Yc-($cover+($DStrand/2)))];
set RS1_Z1strt [expr (($shift*2)+($B/2))-($cover+($DStrand/2))];
set RS1_Y1end [expr -($Yc-($cover+($DStrand/2)))];
set RS1_Z1end [expr (($shift*2)-($B/2))+($cover+($DStrand/2))];
set RS1_Y2strt [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS1_Z2strt [expr (($shift*2)+($B/2))-($cover+($DStrand/2))];
set RS1_Y2end [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS1_Z2end [expr (($shift*2)-($B/2))+($cover+($DStrand/2))];

#FLANGE NUMBER 2
set RS2_Y1strt [expr -($Yc-($cover+($DStrand/2)))];
set RS2_Z1strt [expr ($shift+($B/2))-($cover+($DStrand/2))];
set RS2_Y1end [expr -($Yc-($cover+($DStrand/2)))];
set RS2_Z1end [expr ($shift-($B/2))+($cover+($DStrand/2))];
set RS2_Y2strt [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS2_Z2strt [expr ($shift+($B/2))-($cover+($DStrand/2))];
set RS2_Y2end [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS2_Z2end [expr ($shift-($B/2))+($cover+($DStrand/2))];

#FLANGE NUMBER 3
set RS3_Y1strt [expr -($Yc-($cover+($DStrand/2)))];
set RS3_Z1strt [expr ($B/2)-($cover+($DStrand/2))];
set RS3_Y1end [expr -($Yc-($cover+($DStrand/2)))];
set RS3_Z1end [expr -($B/2)+($cover+($DStrand/2))];
set RS3_Y2strt [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS3_Z2strt [expr ($B/2)-($cover+($DStrand/2))];
set RS3_Y2end [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS3_Z2end [expr -($B/2)+($cover+($DStrand/2))];

#FLANGE NUMBER 4
set RS4_Y1strt [expr -($Yc-($cover+($DStrand/2)))];
set RS4_Z1strt [expr -(($shift-($B/2))+($cover+($DStrand/2)))];
set RS4_Y1end [expr -($Yc-($cover+($DStrand/2)))];
set RS4_Z1end [expr -(($shift+($B/2))-($cover+($DStrand/2)))];
set RS4_Y2strt [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS4_Z2strt [expr -(($shift-($B/2))+($cover+($DStrand/2)))];
set RS4_Y2end [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS4_Z2end [expr -(($shift+($B/2))-($cover+($DStrand/2)))];

#FLANGE NUMBER 5
set RS5_Y1strt [expr -($Yc-($cover+($DStrand/2)))];
set RS5_Z1strt [expr -((($shift*2)-($B/2))+($cover+($DStrand/2)))];
set RS5_Y1end [expr -($Yc-($cover+($DStrand/2)))];
set RS5_Z1end [expr -((($shift*2)+($B/2))-($cover+($DStrand/2)))];
set RS5_Y2strt [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS5_Z2strt [expr -((($shift*2)-($B/2))+($cover+($DStrand/2)))];
set RS5_Y2end [expr -($Yc-($cover+($DStrand/2)+$StrDist))];
set RS5_Z2end [expr -((($shift*2)+($B/2))-($cover+($DStrand/2)))];

#SLAB
#BOTTOM LAYER
set RSSBot_Y1strt [expr (($D-$Yc)+$cover+($DBarSlab/2))];
set RSSBot_Z1strt [expr (($Bslab/2)-($cover+($DBarSlab/2)))];
set RSSBot_Y1end [expr (($D-$Yc)+$cover+($DBarSlab/2))];
set RSSBot_Z1end [expr -(($Bslab/2)-($cover+($DBarSlab/2)))];

#TOP LAYER
set RSSTop_Y1strt [expr (($Dtot-$Yc)-$cover-($DBarSlab/2))];
set RSSTop_Z1strt [expr (($Bslab/2)-($cover+($DBarSlab/2)))];
set RSSTop_Y1end [expr (($Dtot-$Yc)-$cover-($DBarSlab/2))];
set RSSTop_Z1end [expr -(($Bslab/2)-($cover+($DBarSlab/2)))];

section Fiber $id {

#Slab
patch quad $IDcoverConc 400 10 $S_Y1 $S_Z1 $S_Y2 $S_Z2 $S_Y3 $S_Z3 $S_Y4 $S_Z4

#Flange
patch quad $IDcoverConc 40 12 $F1_Y1 $F1_Z1 $F1_Y2 $F1_Z2 $F1_Y3 $F1_Z3 $F1_Y4 $F1_Z4
patch quad $IDcoverConc 40 12 $F2_Y1 $F2_Z1 $F2_Y2 $F2_Z2 $F2_Y3 $F2_Z3 $F2_Y4 $F2_Z4
patch quad $IDcoverConc 40 12 $F3_Y1 $F3_Z1 $F3_Y2 $F3_Z2 $F3_Y3 $F3_Z3 $F3_Y4 $F3_Z4
patch quad $IDcoverConc 40 12 $F4_Y1 $F4_Z1 $F4_Y2 $F4_Z2 $F4_Y3 $F4_Z3 $F4_Y4 $F4_Z4
patch quad $IDcoverConc 40 12 $F5_Y1 $F5_Z1 $F5_Y2 $F5_Z2 $F5_Y3 $F5_Z3 $F5_Y4 $F5_Z4

#Webs
patch quad $IDcoverConc 8 48 $W1_Y1 $W1_Z1 $W1_Y2 $W1_Z2 $W1_Y3 $W1_Z3 $W1_Y4 $W1_Z4
patch quad $IDcoverConc 8 48 $W2_Y1 $W2_Z1 $W2_Y2 $W2_Z2 $W2_Y3 $W2_Z3 $W2_Y4 $W2_Z4
patch quad $IDcoverConc 8 48 $W3_Y1 $W3_Z1 $W3_Y2 $W3_Z2 $W3_Y3 $W3_Z3 $W3_Y4 $W3_Z4
patch quad $IDcoverConc 8 48 $W4_Y1 $W4_Z1 $W4_Y2 $W4_Z2 $W4_Y3 $W4_Z3 $W4_Y4 $W4_Z4
patch quad $IDcoverConc 8 48 $W5_Y1 $W5_Z1 $W5_Y2 $W5_Z2 $W5_Y3 $W5_Z3 $W5_Y4 $W5_Z4
patch quad $IDcoverConc 8 48 $W6_Y1 $W6_Z1 $W6_Y2 $W6_Z2 $W6_Y3 $W6_Z3 $W6_Y4 $W6_Z4
patch quad $IDcoverConc 8 48 $W7_Y1 $W7_Z1 $W7_Y2 $W7_Z2 $W7_Y3 $W7_Z3 $W7_Y4 $W7_Z4
patch quad $IDcoverConc 8 48 $W8_Y1 $W8_Z1 $W8_Y2 $W8_Z2 $W8_Y3 $W8_Z3 $W8_Y4 $W8_Z4
patch quad $IDcoverConc 8 48 $W9_Y1 $W9_Z1 $W9_Y2 $W9_Z2 $W9_Y3 $W9_Z3 $W9_Y4 $W9_Z4
patch quad $IDcoverConc 8 48 $W10_Y1 $W10_Z1 $W10_Y2 $W10_Z2 $W10_Y3 $W10_Z3 $W10_Y4 $W10_Z4

#Reinforcing Steel
#Girder 1
layer straight $IDSteel 18 $Astrand $RS1_Y1strt $RS1_Z1strt $RS1_Y1end $RS1_Z1end
layer straight $IDSteel 16 $Astrand $RS1_Y2strt $RS1_Z2strt $RS1_Y2end $RS1_Z2end
#Girder 2
layer straight $IDSteel 18 $Astrand $RS2_Y1strt $RS2_Z1strt $RS2_Y1end $RS2_Z1end
layer straight $IDSteel 10 $Astrand $RS2_Y2strt $RS2_Z2strt $RS2_Y2end $RS2_Z2end
#Girder 3
layer straight $IDSteel 18 $Astrand $RS3_Y1strt $RS3_Z1strt $RS3_Y1end $RS3_Z1end
layer straight $IDSteel 10 $Astrand $RS3_Y2strt $RS3_Z2strt $RS3_Y2end $RS3_Z2end
#Girder 4
layer straight $IDSteel 18 $Astrand $RS4_Y1strt $RS4_Z1strt $RS4_Y1end $RS4_Z1end
layer straight $IDSteel 10 $Astrand $RS4_Y2strt $RS4_Z2strt $RS4_Y2end $RS4_Z2end
#Girder 5
layer straight $IDSteel 18 $Astrand $RS5_Y1strt $RS5_Z1strt $RS5_Y1end $RS5_Z1end
layer straight $IDSteel 16 $Astrand $RS5_Y2strt $RS5_Z2strt $RS5_Y2end $RS5_Z2end

#Slab
layer straight $IDSteel 69 $ABarSlab $RSSBot_Y1strt $RSSBot_Z1strt $RSSBot_Y1end $RSSBot_Z1end
layer straight $IDSteel 69 $ABarSlab $RSSTop_Y1strt $RSSTop_Z1strt $RSSTop_Y1end $RSSTop_Z1end

};

}; #end of Procedure

[vesna]

Based on the informations you gave me I can not think of anything that will give you zero shear at the section.

However I noticed one error in defining a material for shear. When at the sectional level you need to define shear force - shear deformation relationship rather than shear stress-strain that you defined.

I suggest you to test it on a simple element and to compare sectional shear forces with the element shear forces.

[mairead]

Thanks very much. Am I right in thinking that developing a shear force-deformation relationship for my section which consists of a slab supported by 5 U-Beams would be a very complex task? If I only require the shears at the ends of each element would I be able to get them from the element force recorder (Fy and Fz)? What is the benefit of using the section recorder other than the fact that it gives you the forces all along the element? Thanks

[vesna]

For elements where shear deformations contribute significantly to the total deformation, shear force-deformation relationship needs to be assigned at the sectional level. If shear deformations have negligible influence they can be ignored.

Yes, you can get shear forces at the element ends from the element force recorder.