Verknüpfung von 3D

FEM mit 1D System

Simulation (MOR und

Co-simulation)

Joël Grognuz, CADFEM (Suisse) AG

Mechatronik mit ANSYS Multiphysics

Dynamic analyses overview in ANSYS

Time saving mathematical methods:

1. Transient with MSUP, Rigid Body Dynamics

2. Component Mode synthesis (CMS, Superelements)

3. 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

FEM

2D,3D

+1D

- 4 -

MOR and Co-Simulation:

Model Order Reduction

- 6 -

Limitation: „weak“ Nonlinearities! 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!

Model order Reduction

Model Order Reduktion (MOR):

Get small dimensional Linear State-Space Model (MSUP or Krylov subspace)

cxy

bucxxa

Cxy

BuKxxExM

TPH1

- 8 -

Thermal

Electrical

Multidomain Model Order Reduction (MOR)

Mechanical

(acoustic)

- 9 -

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

- 10 -

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.

Validation: IGBT power module

- 11 -

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.

Relative error

1%

- 12 -

Validation: Comparison with Measurements

Temperatures on IGBTs

Temperatures under IGBTs

- 14 -

13 347 elements

11 765 nodes

55 481 equations to solve

200 frequencies take

about 20 min

with MOR same result

takes 8 second

Validation: MOR quality: Shaker with mounting suspension

- 15 -

Validation: Efficient Simulation of Acoustic FSI with MOR

MOR Example:

Machine tool with

mechatronic

control

Joël Grognuz, CADFEM (Suisse) AG

- 16 -

Goal

- 17 -

3) spindle

2) Machine body 1) Control unit

4) Piece to machine

Study the dynamic interaction between :

Machine tool geometry

- 18 -

the drive chain between

control motor and moving

base is replaced by a

block called „motor“:

The structure

between base

and tool will be

transfered to

simplorer as a

reduced order

model

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!

Motor and transmission Block

- 19 -

Bushing between machine and spindle

In Simplorer

- 20 -

Motor and transmission Block

- 22 -

Rotational

velocity domain

Translational

domain

Coupling

between

rotation

and

translation

(thread)

Torsional

rigidity &

friction

Inertia

wheel

gear box with

efficiency

coef.

Translational

rigidity &

friction

mass

Electrical domain

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

- 29 -

Simplorer-RBD Co-Simulation

Rigid Body Simulation:

Nonlinear large scale motion and reactions:

Co-Simulation:

System behavior 1:1 available in System

Simulation Tool:

- 30 -

Simplorer-RBD cosimulation: Landing Gear Application

- 30 -

- 31 -

Piston Position

Hydraulic Circuit

Simplorer-RBD cosimulation: Landing Gear Application

- 32 -

Simplorer - EM - CFD Cosimulation: solenoid valve

- 32 -

- 33 -

Synchronous Machine with AC-Voltage Excitation

EM 1D+2D: Synchronous motor

Source: CADFEM GmbH

- 34 - Source: CADFEM GmbH

0.00 5.00 10.00 15.00 20.00 25.00 30.00Time [ms]

-15.00

-10.00

-5.00

0.00

5.00

10.00

15.00

Cu

rre

nt

[A]

PESM_PWMWinding Currents ANSOFT

Curve Info

Current(PhaseA)Setup1 : Transient

Current(PhaseB)Setup1 : Transient

Current(PhaseC)Setup1 : Transient

10.00 15.00Time [ms]

-1.00

-0.80

-0.60

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

No

de

Vo

lta

ge

(IV

a)

[kV

]

-150.00

-100.00

-50.00

0.00

50.00

100.00

150.00

-Bra

nch

Cu

rre

nt(

VIA

) [A

]

Ansoft LLC 4_Partial_Motor_TR_PWMPhase Voltage / CurrentSynchronous Machine with PWM Control

EM 1D+2D: Synchronous motor

Further System Simulation

examples

+

-

B 11A 11 C11

A 12 A 2

B 12 B 2

C12 C2

ROT2ROT1

ASMS

3~M

J

STF

M(t)

GN

D

m

STF

F(t)

GN

D

Magnetics

JA

MMF

Mechanics

L

H Q

Hydraulics,

Thermal, ...

Simplorer Simulation Data Bus / Simulator Coupling Technology

Block

Diagrams

State-space

Models (MOR)

Digital/

VHDL

JK-Flip flop with Active-low Preset and Clear

CLK

INV

CLK

CLK

J Q

QB

CLR

PST

Flip flop

K

CLK

CLK

INV

0 0 0 0 1 1 1 1 1 1X-Axis

Curve Data

ffjkcpal1.clk:TR

ffjkcpal1.j:TR

ffjkcpal1.k:TR

ffjkcpal1.clr:TR

ffjkcpal1.pst:TR

ffjkcpal1.q:TR

ffjkcpal1.qb:TR

MX1: 0.1000

PROCESS (CLK,PST,CLR)

BEGIN

IF (PST = '0') THEN

state <= '1';

ELSIF (CLR = '0') THEN

state <= '0';

ENDIF;

statetransition

AUS

SET: TSV1:=0SET: TSV2:=1SET: TSV3:=1SET: TSV4:=0

(R_LAST.I <= I_UGR)

(R_LAST.I >= I_OGR)

EIN

SET: TSV1:=1SET: TSV2:=0SET: TSV3:=0SET: TSV4:=1

State

Graphs

Cxy

BuAxx

Electrical circuits

Multidomain conservative blocks

- 37 -

Battery simulation

Gear

mrv

mtv

mrv

mtv

mrv

mtv

mrv

mtv

ICE_Thr

Reg_brake

Motor_Thr

Brake

DThr

DGear

DBrake

Gear

GN

FD Eng

Eng

Shaf t

TR_ICE

Thr_ICE

MechAcc

Vehicle_mass

100 %

11

2

I

IFuel

CONST

IICEPower

Simplorer car:

Driver

Conservative vehicle model – Physical domains

System design, modeling, assembly testing and

commissioning

Gas cooling System / CERN Geneva

System in underground LHC ATLAS underground

ATLAS

underground areas

Distribution racks

Detector gas cooling system modeled (1D),

built, tested and validated on the surface before

installation and commissioning 100m

underground without any prototype.

Control/ Gas renewal

compressor

- 41 -

Compressor unit (Lumped Parameters)

High Fidelity System Simulation

Ultra High Speed Motor

Fan

Motor

Unit： 〔mm〕

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 2Stator Length 40 mm

Motor

Conv. PWM Inv.

DSP TMS320C6701 FPGA EPF10K30RC240-4

Vdc

V/F Control

Stabilization

Method

High Efficiency

Control

AIO8

DO8

DOM

16

SNC signal

Angle 8bit

Amp 8bit PWM Swiching

Dead Time

Sine Wave

Gate Drive Circuit

6

i u

i v

iw

UHS

High Fidelity System Simulation

Experiment System

VHDL-AMS (digital)

VHDL-AMS VHDL-AMS (or Maxwell)

High Fidelity System Simulation

Ultra High Speed Motor, Complete Model

C/C++

Fan

Motor

Take home: Dynamic analyses overview in ANSYS

Time saving mathematical methods:

1. Transient with MSUP, Rigid Body Dynamics

2. Component Mode synthesis (CMS, Superelements)

3. 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)

- 52 -

FEM

2D,3D

FEM

2D,3D

+1D