From Topology Optimization
to Robust Design Optimization
Dipl.-Ing. Markus Kellermeyer, CADFEM GmbH
Robust Design Optimization
Outline
1. Overview for Optimization in ANSYS Workbench
2. Project Description
3. Topology Optimization inside
ANSYS Workbench
4. Robust Design Optimization with „optiSLang
inside Workbench“
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Robust Design Optimization
Overview for Optimization in ANSYS Workbench
Parameterfree Parameter
optimization optimization
Topology optiSLang optiSLang
Optimization inside with optiPlug
Workbench
Easy-to-use Advanced
tool for difficult tool for all
& nonlinear tasks
optimization
tasks,
robustness
evaluation and
robust design
optimization
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Robust Design Optimization
Example for Topology Optimization: PowerWind GmbH
6 different loadcases were considered
by courtesy of PowerWind GmbH
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Robust Design Optimization
Project Description
Create a design within a predefined space, that
- consists of beams with predefined cross section profiles
- where the beams do not exceed a predefined stress
- where the 1st frequency will be as large as possible
- where the structure will be a 2-σ design or higher due to appearing
stresses
?
? ?
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Robust Design Optimization
Topology Optimization
Steps to do topology optimization with several load cases:
Define several load steps… Run Macro… Solve…
loadcase1
loadcase2
These will represent the
loadcases
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Robust Design Optimization
Topology Optimization
Use Topology Optimization in Workbench
Several load cases can be considered:
a „one-click-solution“
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Robust Design Optimization
Topology Optimization
Use topology idea, to create a manufacturable concept:
Parameterize the beam structure
to allow different design constellations:
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Robust Design Optimization
Topology Optimization
What‘s been done so far:
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
General Information:
Dynardo integrated „optiSLang“ in ANSYS Workbench as an easy-to-
use tool.
It‘s called „optiSLang inside Workbench“
It will be used for the „Robust Design Optimization“ Workflow
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
General Workflow: Optimization 2:
Sensitivity Analysis: Modify Constraints Input1‘ Input4‘
for a new Objectives
Input1 Input2
Optimization Constraints‘
Input3 Input4
Input5 Input6
Input1‘‘ Input4‘‘
Input7 … 1-sigma
level
Robustness Eva. 2:
Optimization:
Input1‘‘ Input2
Input1 Input4 Robustness Eva.: Input3 Input4‘‘
Input1‘ Input2 Input5 Input6 …
Objectives
Constraints Input3 Input4‘ Constraints
Input5 Input6
Input1‘ Input4‘ Input7 …
3-sigma
Constraints level
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
General Workflow in ANSYS Workbench:
Step1 Step2 Step3 Step4 Step5
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 1: Sensitivity Analysis - Setup
1. Define
lower &
upper bounds
2. Define number
of samples
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 1: Sensitivity Analysis - Results
Stress:
Deformation:
Frequency:
Important parameters: split2, split3, split6
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 2: First Optimization
Parameter setting
Define constraints & objectives:
σ < 43.5
d < 0.17
frequency max
Just choose an algorithm.
The ‚decision tree‘ helps!
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 2: First Optimization - Results
Stress = 40.87 < 41.5 (limit)
Deformation = 0.169 < 0.17 (limit)
1st Frequency = 27.9
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 3: Robustness Evaluation with optimized design
The current sigma level for this design is: (41.5-41.16)/0.242 = 1.4
not good enough
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 4: Second Optimization with changed constraint
Define new stress constraint:
σ < 41.2
d < 0.17
frequency max
Stress = 39.0 < 41.5
Deformation = 0.168 < 0.17
1st Frequency = 27.8
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Robust Design Optimization
Robust Design Optimization with „optiSLang inside Workbench“
Step 5: Robustness evaluation with second optimized design
Now, the sigma level is > 2σ
ok! optional: 3rd run with
interpolated stress-
constraint
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Robust Design Optimization
Conclusion
Topology Optimization good for finding a concept
Parametric Optimization good to work with manufacturable
parameters and in more than 1 physics domain
Robust Design Optimization can now be done inside Workbench in
a very quick way: „optiSLang inside Workbench“
easy-to-use tool, that safes time for the user:
90 min
30 min 20 min
10 min setup-time
5 min 5 min 5 min 5 min 5 min
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Robust Design Optimization
Thanks for your attention!
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