Optimization-driven Design at Saab Automobile AB¶nköping 2010-10-07... · ADAMS/Insight...

Optimization-driven Designat Saab Automobile AB

Tomas Sjödin, Engineering Manager, Vehicle SimulationProOpt Workshop, 2010-10-07

Copy right 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

Optimization-driven Design at Saab Automobile AB


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



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:



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



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


Vehicle Systems– Body

– Interior

– Chassis

– Electrical Systems

– HVAC & Powertrain Cooling

– Body

– Interior

– Chassis

– Electrical Systems

– HVAC & Powertrain Cooling


Squeak & Rattles FMH

main defrost

footwell duct rear vent duct

front vent ducts

Thermal – HVAC

Spotweld fatigueClosing

effort

Low speed crash

Airbag deployment


New Saab 9-5 Developed without Hardware Prototypes



Agenda


2. Optimization Standard Work -Today

3. Optimization Standard Work - Tomorrow

4. Q&A



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


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.


-2.5

-2

-1.5

-1

-0.5

0

0.5

1

x 10-7

Sensitivity, 50 Hz, nominal bush rates


Road Noise, Sensitivity & Bushing Investigation, Kriging


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


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.



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 of Airbag Ventilation Hole Size


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



Agenda


2. Optimization Standard Work - Today

3. Optimization Standard Work -Tomorrow

4. Q&A



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.”


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?


Scope of MDO-project



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


Questions?


Optimization-driven Design at Saab Automobile AB¶nköping 2010-10-07... · ADAMS/Insight...

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