2017 UT-SIM Workshop
Outline
Example Structure
Structural configuration
OpenSees Model
Simulation Method
Decomposition
Integration module - OpenSees
Communication overview
Substructure modules
OpenSees
MATLAB
C++
2
2017 UT-SIM Workshop
Example Structure
Loading
4
0
0.2
0.4
0.6
0.8
1
1.2
0 1 2 3 4
PSA
(G
)
Period (s)
Scaled Record vs. Vancouver UHS
Vancouver UHS
Scaled Record
Period Range
of Interest as
per ASCE 7-
10
-5-4-3-2-1012345
0 2 4 6 8 10 12
Gro
un
d a
cce
lera
tio
n, m
/s2
Time, sec
2017 UT-SIM Workshop
Example Structure
OpenSees model
5
Node 1 Node 2
Node 4Node 3
Truss element
Truss element
elasticBeamColumn element
Lumped mass
2017 UT-SIM Workshop
Simulation Method
Decomposition
6
= +
Complete model Integration module Substructure module
2017 UT-SIM Workshop
Simulation Method
Integration module - OpenSees
𝒎 ሷ𝒖 + 𝒄 ሶ𝒖 +
𝒏=𝟐
𝟒
𝒓𝒏 + 𝒓𝟏 = 𝒇(𝒕)
7
Node 1 Node 2
Node 4Node 3
SubStructure
element2 3
4
1
2017 UT-SIM Workshop
Simulation Method
Integration module – OpenSees
Complete model
Integration model
8
Day2: 9:00 – 9:45, Integration Module 1 – OpenSees, Pedram Mortazavi
2017 UT-SIM Workshop
Simulation Method
Communication overview
OpenSees to OpenSees
9
OpenSees 1
Element 1
Element 2
Substructure Element
(SubStructure.dll)DataExchange.dll TCP-IP DataExchange.dll
NICA OpenSees 2
Kinit.txt
Structfile.txt
2017 UT-SIM Workshop
Simulation Method
Communication overview
OpenSees to OpenSees
10
Displacement d1 pattern Plain 999999 Constant {
sp $node $DOF $d1
...
}
Run analysis
Output.txtRead measured force and dispRestoring force r1
Integration NICA OpenSees
UTNP
UTNP
Named Pipe
File I/O
2017 UT-SIM Workshop
Simulation Method
Communication overview
OpenSees to C++/MATLAB
11
OpenSees
Element 1
Element 2
Substructure Element
(SubStructure.dll)DataExchange.dll TCP-IP DataExchange.dll
C++or
MATLAB
Kinit.txt
Structfile.txt
2017 UT-SIM Workshop
Simulation Method
Communication overview
OpenSees to C++/MATLAB
12
Displacement d1 K0*d1
Restoring forceRestoring force r1
UTNP
UTNP
Integration C++/MATLAB
2017 UT-SIM Workshop
Substructure modules
Communication configuration
Port number
Interface nodes and DOFs
13
Node 1 Node 2
Node 4Node 3
(1, 2, 3) (4, 5, 6)
(10, 11, 12)(7, 8, 9)
rz x
y
(x, y, rz)
Integration module Substructure module
Node 1
1 1
Node 12 2
3 3
Node 4
10 4
Node 211 5
12 6
Node 2
(1, 2, 3)
Node 1
(4, 5, 6)
2017 UT-SIM Workshop
Substructure modules
OpenSees
Sub.S2(BRB).tcl
16
Constraints command
Numberer command
System command
Test command
Algorithm command
Integrator command
Analysis command
Analyze command
2017 UT-SIM Workshop
Substructure modules
OpenSees
How to run simulation
▪ Run NICA.exe. In NICA program window, it shows ‘waiting for
connection’.
▪ Run OpenSees integration module.
▪ Once the connection between the integration module and
substructure modules is established, the ‘Press Enter to continue’
message will appear in NICA command window. Click on the NICA
command prompt and press Enter.
17
2017 UT-SIM Workshop
Substructure modules
MATLAB/C++
Communication configuration (i.e. MATLAB)
20
Node 2
(1, 2, 3)
Node 1
(4, 5, 6)
2017 UT-SIM Workshop
Substructure modules
MATLAB/C++
Main loop (i.e. MATLAB)
▪ Receive displacement
▪ Send restoring force
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Can be replaced with the
algorithm for nonlinear elements