Problem in using SFI_MVLEM_3D

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hamidrezaalinejad
Posts: 1
Joined: Tue Apr 04, 2017 7:57 pm
Location: Seoul national university

Problem in using SFI_MVLEM_3D

Post by hamidrezaalinejad » Sun Nov 21, 2021 11:46 pm

Hello all
I faced a strange error for using SFI_MVLEM_3D element for 3D structures.
I’m pretty new to OpenSees, so I’m not sure there is a problem in my modeling or it is related to the element itself.

I was trying to model a 3D structure with core walls and coupling beams.
When I was running the model, the following error appeared and OpenSees was terminated:
“Domain: add node -node with tag -150001 already exist in the model...”
But there is no such node ID in my model (max Node ID was around 4000).

After many try and errors for that model and more simple models, I found that:
* There is no problem in using SFI_MVLEM_3D elements aligned in single vertical plane in 3D space (like 2D model).
* There is no problem in using SFI_MVLEM_3D element with C-shape, L-shape, and T-shape plan.
** But, if the walls are arranged in a closed shape either directly by themselves (like Box-shape plan) or by beams (like four L-shape walls connected by coupling beams), then the same error appears. The only difference was the node ID shown in error, which is smaller for model with fewer nodes (4001, 2001, etc.).

If one set of elements is removed, which changes the close shape to an open shape, then the model works well. For all cases, I checked the results with ETABS, and they were very close. However, based on the cases that I tried, the mentioned set is not fixed, and for some cases, removing a specific set can solve the problem, and removing others does not help.

One more issue is that I thought the problem could be related to the order of element nodes’ ID. So I used ShellMITC4 with the same nodes’ ID, and I found there is no problem.

I prepared a simple 3D model with three stories and closed box-shape core walls to do Eigenvalue analysis. In the model in lines 87-112, there are two sets of elements.
1. If ShellMITC4 is used, then there is no problem.

2. If SFI_MVLEM_3D is used with all elements, then the following error appears and software is terminated.
“Domain: addnode - node with taf -2001already exists in model
WARNING failed to add node to the domain
node: -2001 in SFI_MVLEM”

3. If either 1, 5, and 9 elements or 2, 6, and 10 elements are removed, then the model works. But, if either of 3, 7, and 11 elements or 4, 8, and 12 elements are removed, then the model does not work.

*** This is my code:

wipe
model basic -ndm 3 -ndf 6
# -----------------------------------------------------------------------
# ### 1. Nodes
# -----------------------------------------------------------------------
node 1 0.0 0.0 0.0
node 2 5.0 0.0 0.0
node 3 5.0 5.0 0.0
node 4 0.0 5.0 0.0
node 5 0.0 0.0 3.0
node 6 5.0 0.0 3.0
node 7 5.0 5.0 3.0
node 8 0.0 5.0 3.0
node 9 0.0 0.0 6.0
node 10 5.0 0.0 6.0
node 11 5.0 5.0 6.0
node 12 0.0 5.0 6.0
node 13 0.0 0.0 9.0
node 14 5.0 0.0 9.0
node 15 5.0 5.0 9.0
node 16 0.0 5.0 9.0
node 17 2.5 2.5 3.0
node 18 2.5 2.5 6.0
node 19 2.5 2.5 9.0

# -----------------------------------------------------------------------
# ### 2. Boundary conditions
# -----------------------------------------------------------------------
fix 1 1 1 1 1 1 1
fix 2 1 1 1 1 1 1
fix 3 1 1 1 1 1 1
fix 4 1 1 1 1 1 1
fix 17 0 0 1 1 1 0
fix 18 0 0 1 1 1 0
fix 19 0 0 1 1 1 0

rigidDiaphragm 3 17 5 6 7 8
rigidDiaphragm 3 18 9 10 11 12
rigidDiaphragm 3 19 13 14 15 16

# -----------------------------------------------------------------------
# ### 3. Mass
# -----------------------------------------------------------------------
mass 17 10000.0 10000.0 1.0E-3 0.0 0.0 100.0
mass 18 10000.0 10000.0 1.0E-3 0.0 0.0 100.0
mass 19 10000.0 10000.0 1.0E-3 0.0 0.0 100.0

# -----------------------------------------------------------------------
# ### 4. Material
# -----------------------------------------------------------------------
# Steel material parameters
# ----------------------------
set Es 2.0E11; # Young's modulus
set fy 58.4103; # fy
set b 0.01; # strain hardening
set R0 20.0; # initial value of curvature parameter
set A1 0.925; # curvature degradation parameter
set A2 0.15; # curvature degradation parameter

# ----------------------------
# Concerete material parameters
# ----------------------------
set Ec 30.977E9; # Young's modulus
set fpc 8.09; # peak compressive stress
set ec0 -0.002371; # strain at peak compressive stress
set ft 0.335798; # peak tensile stress
set et 0.00008; # strain at peak tensile stress
set xcrnu 1.022; # cracking strain - compression
set xcrp 10000; # cracking strain - tension
set ru 15; # shape parameter - compression
set rt 1.2; # shape parameter - tension

set rho 0.0074; # X web

set nu 0.2; # friction coefficient
set alfadow 0.012;

uniaxialMaterial SteelMPF 1 $fy $fy $Es $b $b $R0 $A1 $A2;
uniaxialMaterial ConcreteCM 2 -$fpc $ec0 $Ec $ru $xcrnu $ft $et $rt $xcrp -GapClose 0;
nDMaterial FSAM 3 0.0 1 1 2 $rho $rho $nu $alfadow;
# -----------------------------------------------------------------------
# ### 5. Element
# -----------------------------------------------------------------------
# section ElasticMembranePlateSection 1 30.977E9 0.25 0.25 0;
# element ShellMITC4 1 2 1 5 6 1
# element ShellMITC4 2 2 3 7 6 1
# element ShellMITC4 3 3 4 8 7 1
# element ShellMITC4 4 1 4 8 5 1
# element ShellMITC4 5 6 5 9 10 1
# element ShellMITC4 6 6 7 11 10 1
# element ShellMITC4 7 7 8 12 11 1
# element ShellMITC4 8 5 8 12 9 1
# element ShellMITC4 9 10 9 13 14 1
# element ShellMITC4 10 10 11 15 14 1
# element ShellMITC4 11 11 12 16 15 1
# element ShellMITC4 12 9 12 16 13 1

element SFI_MVLEM_3D 1 2 1 5 6 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 2 2 3 7 6 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 3 3 4 8 7 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 4 1 4 8 5 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 5 6 5 9 10 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 6 6 7 11 10 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 7 7 8 12 11 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 8 5 8 12 9 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 9 10 9 13 14 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 10 10 11 15 14 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 11 11 12 16 15 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3
element SFI_MVLEM_3D 12 9 12 16 13 5 -thick 0.25 0.25 0.25 0.25 0.25 -width 1.0 1.0 1.0 1.0 1.0 -mat 3 3 3 3 3

# -----------------------------------------------------------------------
# ### 6. Analysis
# -----------------------------------------------------------------------
set eig [eigen 3]
record

# -----------------------------------------------------------------------
# ### 7. Post-processing
# -----------------------------------------------------------------------
puts "Mode-1 Period is:[expr 2*3.1415/pow([lindex $eig 0],0.5)]"
puts "Mode-1 Period is:[expr 2*3.1415/pow([lindex $eig 1],0.5)]"
puts "Mode-1 Period is:[expr 2*3.1415/pow([lindex $eig 2],0.5)]"

recorder display "Mode Shape 1" 10 10 500 500 -wipe
prp 2.5 1 4.5;
vup 0 0 1;
vpn -1 -1 -1;
viewWindow -10 10 -10 10;
display -1 1 50;

recorder display "Mode Shape 2" 550 10 500 500 -wipe
prp 2.5 1 4.5;
vup 0 0 1;
vpn -1 -1 -1;
viewWindow -10 10 -10 10;
display -2 1 50;

recorder display "Mode Shape 3" 1100 10 500 500 -wipe
prp 2.5 1 4.5;
vup 0 0 1;
vpn -1 -1 -1;
viewWindow -10 10 -10 10;
display -3 1 50;

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