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I am getting some error while executing the zero length element for interface simulation. Can you please tell me the reason behind and solution for it.

WARNING ZeroLengthContact3D::setDomain(): Element 7 has L= 1.41421, which is greater than the tolerance

The syntax for zerolength contact element is given below:
element zeroLengthContact3D $eleTag $sNode $mNode $Kn $Kt $mu $c $dir

Please reply. It will a great help to me.

Please do reply

This is the command used for defining the inteface in 3D modelling

element zeroLengthContact3D $eleTag $sNode $mNode $Kn $Kt $mu $c $dir

Can you please tell me the use of c (cohesion) here and how to define its value.

Thank you sir

Dear Sir,

I am using 2.3.2 version. please tell me what is the correct format as per that

I am using brick element

I have a doubt about the recording format of stresses of an element. As per xml file, it is in this format: xx-stress, yy-stress, zz-stress, xy-stress, xz-stress, yz-stress, whereas the results look like to be in this format: xx-stress, yy-stress, zz-stress, xy-stress, yz-stress, xz-stress. Please make me clear which one is correct.

I will wait for your reply.

Dear Ma'am,

Thank you for reply. I have one query. I have brick element to simulate my 3D problem. Now I want to calculate the bending moment. Can you please tell me how to calculate that as force recorder only provide the shear forces.

I will wait for your reply.

Thank you

Can you please tell me the output format of forces recorded for a brick element.

I want to calculate the bending moment of a brick element. Can you please tell me how to do it.

Can you please tell me how to use pressure Independent Multi Yield material model for the static constant loading in order to get nonlinear response. I tried to use this model, but I am getting the linear response.

Can you please tell me the maximum number of dof that can be handled by the OPENSEES. Actually, I am having the DOF more that 1.5lakh. And I am not getting any results.

Actually, the value of the load has to be constant. Here is my code. I reduce its length.


wipe;
model BasicBuilder -ndm 3 -ndf 3;
node 3 0 0 29.5; #0.5
node 4 0 0 28.5; #1.5
node 5 0 0 27.5; #2.5
node 6 0 0 26.5; #3.5
node 7 0 0 25.5; #4.5
# node for spring end is created.

node 301 1 0 29.5;
node 401 1 0 28.5;
node 501 1 0 27.5;
node 601 1 0 26.5;
node 701 1 0 25.5;
# node for the spring start is calculated...

fix 3 1 1 1;
fix 4 1 1 1;
fix 5 1 1 1;
fix 6 1 1 1;
fix 7 1 1 1;
# base of spring is fixed


fix 301 0 1 1;
fix 401 0 1 1;
fix 501 0 1 1;
fix 601 0 1 1;
fix 701 0 1 1;
# springs are allowed to move in x-direction only.
set strain {0.00001 0.00002 0.00003 0.00004 0.00005 }
set strain_factor {0.955 0.925 0.905 0.885 0.865}
set G_max {
104265
169540
234816
656797
1078779
}

set spring_factor 1
set strain_incr 0
set deflection 0.0015
set deflection1 [expr $deflection+0.1*$deflection]
set deflection2 [expr $deflection-0.1*$deflection]
set n [llength $strain]
set l [llength $G_max]
for {set i 1} {$i<=$n} {incr i 1} {
puts "\n\n Iteration $i \n"
set S($i) [lindex $strain $strain_incr]
puts "strain $S($i)"
set SF($i) [lindex $strain_factor $strain_incr]
puts "strain_factor $SF($i)"
set G_incr 0
for {set j 1} {$j<=$l} {incr j 1} {

set G_maximum($j) [lindex $G_max $G_incr]
set G($j) [expr $SF($i)*$G_maximum($j)]
set k($j) [expr $G($j)*$spring_factor]
incr G_incr
}
puts "$G(1) $G(2) $G(3)";

uniaxialMaterial Elastic 300$i [expr $k(1) ] 0;
uniaxialMaterial Elastic 400$i [expr $k(2) ] 0;
uniaxialMaterial Elastic 500$i [expr $k(3) ] 0;
uniaxialMaterial Elastic 600$i [expr $k(4) ] 0;
uniaxialMaterial Elastic 700$i [expr $k(5) ] 0;

element truss 300$i 3 301 1 300$i;
element truss 400$i 4 401 1 400$i;
element truss 500$i 5 501 1 500$i;
element truss 600$i 6 601 1 600$i;
element truss 700$i 7 701 1 700$i;

if {$i == 1} {
model BasicBuilder -ndm 3 -ndf 6;
set transTag 1;
geomTransf Linear $transTag 0 -1 0;
node 3511 1 0 30.6;
node 3411 1 0 30.1;
node 311 1 0 29.5;
node 411 1 0 28.5;
node 511 1 0 27.5;
node 611 1 0 26.5;
node 711 1 0 25.5;
node 811 1 0 24.5;

fix 3511 0 1 0 1 0 1;
fix 3411 0 1 0 1 0 1;
fix 311 0 1 0 1 0 1;
fix 411 0 1 0 1 0 1;
fix 511 0 1 0 1 0 1;
fix 611 0 1 0 1 0 1;
fix 711 0 1 0 1 0 1;
fix 811 0 1 1 1 0 1;

equalDOF 311 301 1;
equalDOF 411 401 1;
equalDOF 511 501 1;
equalDOF 611 601 1;
equalDOF 711 701 1;


set pi 3.14;
set r 1.2;
set a [expr $pi*$r*$r/4];
set I [expr $pi*$r*$r*$r*$r/4.0];
set J [expr 2*$I];
set E [expr 29.58e06*1.0]; #M35 grade
set nu 0.3;
set G_pile [expr $E/(2.0*(1.0+$nu))]
set nIntpts 3;
set sectag 1;
set sectag3D 3;
section Elastic $sectag $E $a $I $I $G_pile $J;
uniaxialMaterial Elastic 100 1.e10;
section Aggregator $sectag3D 100 T -section $sectag


# create pile element

element dispBeamColumn 3511 3511 3411 $nIntpts $sectag3D $transTag;
element dispBeamColumn 3411 3411 311 $nIntpts $sectag3D $transTag;
element dispBeamColumn 311 311 411 $nIntpts $sectag3D $transTag;
element dispBeamColumn 411 411 511 $nIntpts $sectag3D $transTag;
element dispBeamColumn 511 511 611 $nIntpts $sectag3D $transTag;
element dispBeamColumn 611 611 711 $nIntpts $sectag3D $transTag;
element dispBeamColumn 711 711 811 $nIntpts $sectag3D $transTag;
}
pattern Plain 1 Constant {
load 3511 100 0 0 0 0 0;
}

file mkdir disp
recorder Node -file disp/pyDisplace.out -time -node 3511 3411 301 401 501 601 701 -dof 1 disp;
recorder Node -file disp/pyforces.out -time -node 3 4 5 6 7 -dof 1 reaction;

integrator LoadControl 1;
numberer Plain;
system BandGeneral;
constraints Transformation;
algorithm Linear;
analysis Static;
set startT [clock seconds]
analyze 1;
set endT [clock seconds]
puts " analysis execution time : [expr $endT -$startT] seconds"
remove recorders
remove loadPattern 1

set cal_top_disp [nodeDisp 3511 1]
set top_disp [format "%6.8f" $cal_top_disp]
puts "top_disp $top_disp"
if { $top_disp >= $deflection2} {
if { $top_disp <=$deflection1} {
puts $S($i)
puts $deflection
break;
}
}
incr strain_incr
}
puts "done"


Here, you can see that the stiffness of the truss element changes in every loop and load is constant throughout the code. But, I am getting the same displacement for every loop. However, it should increase with loop number.

Now, I think that you have understand my problem. Please tell me how to overcome this problem

I want to know how to apply a load in a loop so that we will have same load everytime in a loop.

I tried constant - getting same results for each loop.
Linear - results are different, but giving very high value.
Rectangular - giving same results as the constant load command

Actually, I want to tell you one more thing, I am using elastic isotropic material whose strength is changing in each loop. I am calculating the displacement corresponding to that strength. Hence, I use constant load pattern in each loop. Now, I don't thing so, there will a ant problem in using constant load pattern.