Mechatronik mit ANSYS Multiphysics
Verknüpfung von 3D
FEM mit 1D System
Simulation (MOR und
Co-simulation)
Joël Grognuz, CADFEM (Suisse) AG
Dynamic analyses overview in ANSYS
 Time saving mathematical methods:
FEM
2D,3D
1. Transient with MSUP, Rigid Body Dynamics
2. Component Mode synthesis (CMS, Superelements)
Circuit or PID 1D Elements embeded
in the same FEM model
4. Simplorer with State space matrices obtained by Model Order
Reduction (MOR for ANSYS, SPMWRITE in ANSYS Mechanical)
5. Cosimulation between Simplorer and rigid body dynamics (RBD)
3.
FEM
2D,3D
+1D
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MOR and Co-Simulation:
-4-
Model Order Reduction
Model order Reduction
Mx  Ex  Kx  Bu
y  Cx
 Model Order Reduktion (MOR):
Get small dimensional Linear State-Space Model (MSUP or Krylov subspace)
ax  cx  bu
y  cx
Limitation: „weak“ Nonlinearities!
TPH1
1. Small Amplitudes only
2. Contact status unchanged
 Linearization at nonlin status possible
(large deformation, pre-stress, contact
status frozen , …)
Electronic component modeling and controller design may be fully nonlinear!
-6-
Multidomain Model Order Reduction (MOR)
Mechanical
(acoustic)
Thermal
Electrical
-8-
Validation: MOR quality: Mechanical example: hard disk drive head
 3352 elements
 7344 nodes
 21227 equation
 FEM:
400 frequencies takes about 12
min
 MOR takes only 3 s
 Comparison for head

ANSYS 21k DOF

MOR
30 DOF

MOR
80 DOF
-9-
Validation: IGBT power module
 12 inputs and outputs have been defined
DoFs:
ANSYS full model
> 900 000.
Reduced model:
15 DoFs per input =
15*12 = 180.
 The reduced model covers all heat sources
and thermal cross talk at once.
- 10 -
Validation: Comparison ANSYS Full  MOR
 Red line – ANSYS, green line – reduced model. Difference is close to
the line thickness. For such accuracy, one needs 15 DoFs per input.
1%
 Relative error
- 11 -
Validation: Comparison with Measurements
Temperatures on IGBTs
- 12 -
Temperatures under IGBTs
Validation: MOR quality: Shaker with mounting suspension
 13 347 elements
 11 765 nodes
 55 481 equations to solve
 200 frequencies take
about 20 min
 with MOR same result
takes 8 second
- 14 -
Validation: Efficient Simulation of Acoustic FSI with MOR
- 15 -
MOR Example:
Machine tool with
mechatronic
control
Joël Grognuz, CADFEM (Suisse) AG
- 16 -
Goal
Study the dynamic interaction between :
1) Control unit
2) Machine body
3) spindle
4) Piece to machine
- 17 -
Machine tool geometry
The structure
between base
and tool will be
transfered to
simplorer as a
reduced order
model
the drive chain between
control motor and moving
base is replaced by a
block called „motor“:
The remainder of the
structure was negleted in
this workshop for
simplicity but should
indeed be kept in order to
obtain accurate results;
the focus of this
workshop is on
modelling techniques,
not on accuracy!
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Motor and transmission Block
- 19 -
Bushing between machine and spindle
 In Simplorer
- 20 -
Motor and transmission Block
Electrical domain
Coupling
between
rotation
Translational
and
domain
translation
(thread)
Rotational
velocity domain
Torsional Inertia gear box with
rigidity &
efficiency
wheel
friction
coef.
- 22 -
Translational mass
rigidity &
friction
Machine control study
MOR & Verification: WB transient versus Simplorer
Transient FE-Analysis in WB: ca. 1h
Reduced model in Simplorer: 4 seconds
Machine control study
Position Control with simple PID: too slow! Tsettling = 8,3 s
Machine control study
Position Control with cascaded speed controller:
Optimized 
Tsettling = 2 s
Tsettling = 0,75 s
Co-simulation
Simplorer-RBD Co-Simulation
Rigid Body Simulation:
Nonlinear large scale motion and reactions:
Co-Simulation:
System behavior 1:1 available in System
Simulation Tool:
- 29 -
Simplorer-RBD cosimulation: Landing Gear Application
- 30 -
- 30 -
Simplorer-RBD cosimulation: Landing Gear Application
Hydraulic Circuit
Piston Position
- 31 -
Simplorer - EM - CFD Cosimulation: solenoid valve
- 32 -
- 32 -
EM 1D+2D: Synchronous motor
Synchronous Machine with AC-Voltage Excitation
- 33 -
Source: CADFEM GmbH
EM 1D+2D: Synchronous motor
Synchronous Machine with PWM Control
Ansoft LLC
Phase Voltage / Current
4_Partial_Motor_TR_PWM
150.00
1.00
0.80
100.00
0.60
15.00
Current(PhaseA)
Setup1 : Transient
Current(PhaseB)
Setup1 : Transient
Current(PhaseC)
Setup1 : Transient
10.00
0.40
ANSOFT
Curve Info
50.00
0.20
0.00
0.00
-0.20
-50.00
-0.40
-0.60
-100.00
-0.80
-150.00
10.00
-1.00
15.00
Time [ms]
Current [A]
5.00
0.00
-5.00
-10.00
-15.00
0.00
- 34 -
5.00
Source: CADFEM GmbH
10.00
15.00
Time [ms]
20.00
25.00
30.00
NodeVoltage(IVa) [kV]
PESM_PWM
-BranchCurrent(VIA) [A]
Winding Currents
Further System Simulation
examples
Multidomain conservative blocks
Electrical circuits
Magnetics
Mechanics
J
Hydraulics,
Thermal, ...
A 11B 11C 11
B 12
M
3~
C 12
A2
M( t)
B2
STF
MMF
C2
GND
A 12
L
JA
+
R OT1
R OT2
-
F( t)
m
STF
GND
ASMS
Q
H
Simplorer Simulation Data Bus / Simulator Coupling Technology
CLK
ffj
INV
ffj
ffj
ffj
CLK
ffj
PST
State-space
Models (MOR)
Block
Diagrams
State
Graphs
Digital/
VHDL
J
Q
CLK
Flip flop
QB
CLR
CLK
CLK
INV
state
transition
PROCESS (CLK,PST,CLR)
EIN
BEGIN
SET: TSV1:=1
SET: TSV2:=0
SET: TSV3:=0
SET: TSV4:=1
x  Ax  Bu
y  Cx
IF (PST = '0') THEN
(R_LAST.I >= I_OGR)
state <= '1';
ELSIF (CLR = '0') THEN
AUS
(R_LAST.I <= I_UGR)
SET: TSV1:=0
SET: TSV2:=1
SET: TSV3:=1
SET: TSV4:=0
state <= '0';
ENDIF;
ffj
ffj
K
Battery simulation
- 37 -
Conservative vehicle model – Physical domains
 Simplorer car:

Driver
Gear
DThr
Motor_Thr
DBrake
Reg_brake
DGear
ICE_Thr
Brake
Gear
mrv
mrv
mtv
mtv
GN
Thr_ICE
100 %
2
1
FD
Eng
TR_ICE
Eng
MechAcc
mrv
mrv
mtv
mtv
Shaf t
Vehicle_mass
IFuel
CONST
I
Gas cooling System / CERN Geneva
System design, modeling, assembly testing and
commissioning
System in underground LHC ATLAS underground
 Detector gas cooling system modeled (1D),
built, tested and validated on the surface before
installation and commissioning 100m
underground without any prototype.
ATLAS
underground areas
Control/ Gas renewal
Distribution racks
compressor
Compressor unit (Lumped Parameters)
- 41 -
High Fidelity System Simulation
Ultra High Speed Motor
Unit： 〔mm〕
Fan
Motor
Aspects of the Motor design
(1) Surface type permanent magnet synchronous motor
(2) Rotor surface is covered by the inconel material for
shatterproof of the magnet
(3) Protection from oil infiltration
(4) Concentrated winding is employed.
Rated Output
5 kW
Rated Voltage
200 V
Rated Speed
240,000 rpm
Number of Poles
2
Stator Length
40 mm
High Fidelity System Simulation
Experiment System
FPGA
DSP TMS320C6701
V/F Control
Stabilization
Method
High Efficiency
Control
DO8
EPF10K30RC240-4
SNC signal
Sine Wave
Amp 8bit
DOM Angle 8bit
16
PWM Swiching
Dead Time
Gate Drive Circuit
AIO8
6
V dc
iu
iv
iw
Conv.
PWM Inv.
UHS
Motor
High Fidelity System Simulation
Ultra High Speed Motor, Complete Model
C/C++
VHDL-AMS (digital)
Fan
Motor
VHDL-AMS
VHDL-AMS (or Maxwell)
Take home: Dynamic analyses overview in ANSYS
 Time saving mathematical methods:
FEM
2D,3D
1. Transient with MSUP, Rigid Body Dynamics
2. Component Mode synthesis (CMS, Superelements)
Circuit or PID 1D Elements embeded
in the same FEM model
4. Simplorer with State space matrices obtained by Model Order
Reduction (MOR for ANSYS, SPMWRITE in ANSYS Mechanical)
5. Cosimulation between Simplorer and rigid body dynamics (RBD)
3.
FEM
2D,3D
+1D
- 52 -