optimization-driven design at saab automobile ab¶nköping 2010-10-07... · adams/insight...
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Optimization-driven Designat Saab Automobile AB
Tomas Sjödin, Engineering Manager, Vehicle SimulationProOpt Workshop, 2010-10-07
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Agenda
1. Introduction to CAE at Saab Automobile AB
2. Optimization Standard Work - Today
3. Optimization Standard Work - Tomorrow
4. Q&A
Optimization-driven Design at Saab Automobile AB
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We Believe in CAE!
We have learned that by using CAE in an efficient way we get:
Significant time reductions
Product cost savings
Quality improvement (achieve consistent performance)
Increased product design innovation
Optimization-driven Design at Saab Automobile AB
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Past:
Hardware-based
development
build and test
– 6 months
Engineering
start
Start of
production
Mules
Hardware vehicles phases:
Prot. 1 … Prot. N Pilot
Now:
CAE-driven
development
build and test
– 6 weeks
From Hardware-based to CAE-driven Development
Virtual Vehicles Phases
VA 1
Mules Pilot
Engineering
start
Start of
production
VA 2 … VA N
Hardware vehicles phases:
Optimization-driven Design at Saab Automobile AB
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Hybrid Organisation – Combining Benefits
CAE groups report to two organisations:
Vehicle Simulation – direct organisation
Product Functional Organization - indirect organization
StiffnessStrengthDurabilityetc.
Interior
CAE
Chassis
CAE
Body
CAE
Safety
CAE
Aero
CAE
VD
CAE
NVH
CAE
CAE
Optimization-driven Design at Saab Automobile AB
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CAE
– Aerodynamics
– Energy
– Human Vehicle Integration
– Noise & Vibration
– Safety
– Vehicle Dynamics
Vehicle Integration– Aerodynamics
– Energy
– Human Vehicle Integration
– Noise & Vibration
– Safety
– Vehicle Dynamics
– Physical Integration
Vehicle Architecture– Physical Integration
CAE is the Engine in the Daily Development Work
Optimization-driven Design at Saab Automobile AB
Vehicle Systems– Body
– Interior
– Chassis
– Electrical Systems
– HVAC & Powertrain Cooling
– Body
– Interior
– Chassis
– Electrical Systems
– HVAC & Powertrain Cooling
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Squeak & Rattles FMH
main defrost
footwell duct rear vent duct
front vent ducts
Thermal – HVAC
Spotweld fatigueClosing
effort
Low speed crash
Airbag deployment
Optimization-driven Design at Saab Automobile AB
New Saab 9-5 Developed without Hardware Prototypes
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Optimization-driven Design at Saab Automobile AB
Agenda
1. Introduction to CAE at Saab Automobile AB
2. Optimization Standard Work -Today
3. Optimization Standard Work - Tomorrow
4. Q&A
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Optimization-driven Design at Saab Automobile AB
Optimization Standard Work – Today
Optimizations across CAE-groups are performed manually
Process:
1. Optimization of one
loadcase / discipline
2. Check results in other
loadcases / disciplines
and adjust
Optimization
of one
loadcase /
discipline
Check results
for other
loadcases /
disciplines
Proposal from Optimization
Adjustments
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Noise and Vibration Optimization
A panel sensitivity and contribution study has been conducted for finding out
what is causing the increased WOT SPL at the rear right seat position at 50 Hz.
The studies have been made on the full vehicle model using the WOT load at the mentioned
frequency.
Panel sensitivities show the sensitivity of the SPL to a thickness change of the panel.
A positive sensitivity should indicate that increasing the thickness leads to a higher SPL.
Panel contributions show how much each panel is contributing to the SPL.
Optimization-driven Design at Saab Automobile AB
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
x 10-7
Sensitivity, 50 Hz, nominal bush rates
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Road Noise, Sensitivity & Bushing Investigation, Kriging
Optimization-driven Design at Saab Automobile AB
0% 20% 40% 60% 80% 100%
Ste2Cr_yz
lcaFr_yz
CrFR_y
CrFr_x
CrRe_x
lcaRe_yz
Ste2Cr_yz * lcaRe_yz
CrRe_x * CrFR_y
lcaRe_yz * lcaFr_yz
lcaRe_yz * CrFR_y
Percent Contribution
Main Effect Plots
(With Overall Mean Added In)
3,11E+01
3,40E+01
3,69E+01
3,98E+01
4,27E+01
4,56E+01
0% 20% 40% 60% 80% 100%
Percent Way From Lower to Upper Bound
Valu
e o
f
Ste2Cr_yz
lcaFr_yz
CrFR_y
lcaRe_yz
CrRe_x
CrFr_x
St2Ce_x
lcaRe_x
St2Cr_yz
CrRe_y
Driver’s ear
@220 Hz
Road noise from front suspension, McPherson
Sensitivity study:
Driver’s ear @220 Hz:
McPherson & Hiperstrut
• Cradle to body rear global Y softer
• Cradle to body rear global X softer
• Cradle to body front global X softer
• Steering gear to cradle axial & radial softer
• Lower control arm front & rear to cradle radial softer
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Optimization of Hood and Decklid - Maneuvering Forces Scope:
Find optimal combination of gas spring parameters (F1, X and position in closure) within given package space to find
most optimal and balanced handling forces in both opening and closing and extreme temperatures.
Program:
ADAMS/Insight
Optimization:
Start with a Parameterized ADAMS model for handling. Define Design Variables and Design Objectives. Set up
experiment, run experiment and fit into a response surface, export response surface to Excel format for further
studies by CAE analyst as well as design engineer.
Optimization-driven Design at Saab Automobile AB
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Manual Optimization, FMVSS201U, Free Motion HeadformScope:
Within a given package space, study the performance of different designs of energy absorbers relative to
the legal requirement of 1000 HIC(d) according to FMVSS201U. (HIC = Head Injury Criteria)
• Conceptual: Comparing performance between different type of absorbers, for example:
foams, rib structures, metal brackets
• Optimization: Varying energy absorber parameters such as, foam densities, height and
thickness of ribs, number of ribs.
Example below: Different variants of a honeycomb. Different thickness and
height of ribs.
Optimization-driven Design at Saab Automobile AB
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Optimization of Airbag Ventilation Hole Size
Optimization-driven Design at Saab Automobile AB
Stiffness of airbag is varied with different ventilation hole sizes
Goal for optimization is to reduce injury levels
Optimization in a project is done with respect of:
• Different loadcases; angle and speed
• Belted and unbelted dummies
• Different dummy sizes
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Optimization-driven Design at Saab Automobile AB
Agenda
1. Introduction to CAE at Saab Automobile AB
2. Optimization Standard Work - Today
3. Optimization Standard Work -Tomorrow
4. Q&A
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Optimization-driven Design at Saab Automobile AB
Optimization Standard Work – Tomorrow
Optimizations are performed multidisciplinary – MDO
Early: Help to choose the right concepts with potential to meet all defined requirements, i.e. prevent costly and
mass inefficient solutions due to late changes.
Later: Help to optimize the defined design to minimize weight while still meeting all defined performance targets.
Process:
1. Optimization of many
loadcases / disciplines
at the same time
2. Make balanced design
decisions
Optimizationof many
loadcases / disciplines at
the same time
MDO = Multidisciplinary
Design Optimization
“How to decide what to
change, and to what
extent to change it, when
everything influences
everything else.”
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What?
• Which systems and loadcases are suitable for MDO and how should they be identified?
When?• When should different types of optimization be done?
How?• What methods and settings should be used?
Who?• Who should perform MDO and what is a suitable organization?
Optimization-driven Design at Saab Automobile AB
Scope of MDO-project
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Optimization-driven Design at Saab Automobile AB
Optimization Standard Work – Tomorrow
Benefits
Shorter development times
Improved performance
Balanced designs
More focus on complete vehicle
performance
Challenges
Computer resources
Processes that enables MDO
Pareto Frontier =
Set of optimized solutions
Component
Validation
Subsystem
Validation
Vehicle
Validation
Component
Requirements
Subsystem
Requirements
Vehicle
Requirements
Customer
Expectation
Validated
Product
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Questions?
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