Upload
tranhuong
View
234
Download
0
Embed Size (px)
Citation preview
Stand: 28.10.05 EM5/ALH 09.11.05 1
Copyright HELLER
Topology Optimization of Machine Tools to improve the
Stability in high performing Metal Cutting Processes
Gebr. HELLER Maschinenfabrik GmbHDr. Gerhard Kehl, Harald Altstädter
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 2
Manufacturing Systems for Automotive Industry
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 3
MCH 250 G
MCH 350 GE
MCH 250 C
MCH 250 HSM
Simulation Disciplines at Machine Tools
Static Dynamic
Thermal
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 4
Mechanical Structures in complex Systems
Designspace
Non-Desigarea
2 Volumes
3 Couplings
17 Volumes
12 elastic Couplings
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 5
Modeling of the mechanical Structure for Optimization
+ =
Non-Design Area Designspace Simulation Model
+ =
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 6
Optimization Strategies
Combined Topology Optimizationstatic loads + eigenfrequencies
specific frequency constraints
f1= 60 Hz > f
1*
f2= 90 Hz > f
2*
f3= 120 Hz > f
3*
Static Topology Optimization with weighted load cases (up to now max. 44)
• moving loads (weight)
• acceleration loads (quasi-static)
• process loads
Frequenz
Am
plitu
de
Ausgangsmodell
Opt imierungsergebnis
(Nachgiebigkeitsf requenzgang)
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 7
Initial model for head (Realistic boundary conditions)
Loadcase 1(x-direction)
Flexible beam elements for
boundary conditions
Beam elements
attached
to rigid mass
Loadcase 2 (y-direction)
Beam elements
attached
to rigid mass
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 8
Static optimization
Minimize: Maximize of { abs(ux), abs(uy)}
Mass < Mass* = 35%
Important: the static optimization
showed that the frequency responses also
have to be considered in the optimization.
The rigid mass is no
more
attached to structure !!!!
Number Eigenfrequency
1 ~0
2 ~0
3 ~0
4 2.4
5 3.0
6 3.5
}
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 9
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
1 3 5 7 9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
Frequency optimization
Maximize the eigenfrequencies from f1 to f6
Mass < Mass* = 35%
Mass constraint is not active
Important: Model the correct physical
boundary conditions. The optimization
should include static and frequency results.
Number Eigenfrequency
1 83
2 105
3 112
Shaft hardly attached to structure.
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 10
Combined static and frequency optimization
Purpose: To improve the static stiffness for both loadcases including constraints
on the eigenfrequencies.
Objective: Minimize: Maximize of { abs(ux), abs(uy)}
Constraints: Mass < Mass* = 35%
f1> f
1* = 60 Hz f
1> f
1* = 75 Hz
f2> f
2* = 90 Hz f
2> f
2* = 100 Hz
f3> f
3* = 120 Hz f
3> f
3* = 125 Hz
f4> f
4* = 150 Hz f
4> f
4* = 150 Hz
f5> f
5* = 180 Hz f
5> f
5* = 175 Hz
f6> f
6* = 210 Hz f
6> f
6* = 200 Hz
Example 1
Example 2
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 11
Combined static and frequency optimization: Topology
Example 1:
Number Initial example 1
1 48 60
2 60 90
3 94 137
4 137 181
5 260 256
6 265 345
Example 2:
Number Initial example 2
1 48 75
2 60 101
3 94 145
4 137 191
5 260 268
6 265 377
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 12
Examples for Topology optimized Machine Components
Tool Changer Arm Rod and Plain Eye hydr. Rundtisch Brake
p
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 13
Examples for Topology optimized Machine Components
Machine Stand
Copyright HELLER
Vers: 28.10.05EM5/ALH 09.11.05 14
Examples for Topology optimized Machine Components
Machine Stand
Milling and Boring Carriage