icme 3gahss: design & cae optimization of …/media/files/autosteel/great designs in...

GDIS2017

ICME 3GAHSS: DESIGN & CAE OPTIMIZATION OF

LIGHTWEIGHT VEHICLE ASSEMBLY

Eric McCarty

Auto/Steel Partnership

Harry Singh

EDAG, Inc.

#GDIS | #SteelMatters 2

Highlights

INTEGRATED COMPUTATIONAL MATERIALS

ENGINEERING APPROACH TO DEVELOPMENT OF

LIGHTWEIGHT 3GAHSS VEHICLE ASSEMBLY

• Principal Investigator: Dr. Lou Hector Jr. (GM)

• 4+ Year Project - Feb. 1, 2013 – Mar. 31, 2017

• $8.5 Million - $6M DOE, $2.5M Cost Share

• Participants: - 5 universities - 1 national laboratory

- 3 steel companies - 3 automotive OEMs

- 2 engineering firms


Participants

Universities / National Labs Industry Consortiums

Brown University FCA US LLC Auto/Steel Partnership

Clemson University Ford Motor Company United States Automotive Materials Partnership

Colorado School of Mines General Motors Company

Pacific Northwest National Lab ArcelorMittal

Ohio State University AK Steel Corporation

University of Illinois at Urbana-Champaign Nucor Steel Corporation

EDAG

LSTC


Steel Strength Ductility Diagram

• Two 3GAHSS steels were developed for model validation and design optimization.

Steel YS (MPa) UTS (MPa) Total Elongation

High Strength, Exceptional Ductility 750 1,200 37%

Exceptional Strength, High Ductility 1,218 1,538 20%


3GAHSS

• The two 3GAHSS alloys were used for:

Engineering strain

0.00 0.05 0.10 0.15 0.20

Engin

eering s

tress (

MP

a)

0

200

400

600

800

1000

1200

1400

1600

Exp. (Uniaxial tension)

UTS (Exp.)

RVE1 (: 57.4%, ': 25.1%, : 17.5%)

UTS (RVE1)

Phase distribution

Tempered martensite (57.4 %)

Austenite (17.5 %)

Untempered martensite (25.1 %)

Material Model Validation Forming Model Validation Design Optimization

Body Side Assembly (LH &

RH) 46 Stampings


Task 5 – Program Requirement

Vehicle

System System Definition (1)

Weight

Reduction

Target (2)

Cost per Pound of

Weight Saved ($/lb

saved) (2)

Additional

Requirements

Body

Body-in-White, Closures,

Windows, Fenders, & Bumpers ≥35% ≤$3.18/lb

Replacement

Technology must

achieve Function and

Packaging

Requirements of

Technology to be

Replaced

Chassis

Suspension, Steering, Wheels, &

Underbody Structural

Components ≥25% ≤$3.11/lb

Note (2): When compared to a 2006 or Later Production Light Duty Vehicle Technologies.

Baseline Assembly

Applicants shall establish a baseline vehicle assembly for comparison. The baseline

vehicle assembly description shall include the assembly description, its materials of

construction, and weight. Baseline vehicle components shall have been available on

a similarly configured 2006 or later commercially available Light Duty production

vehicle. Light Duty vehicles include any of the following automobiles: passenger

vehicles, light duty trucks, sport utility vehicles, or passenger vans.


Establish Baseline Assemblies:

1. Select Assemblies

2. Load Cases and Performance Targets (Stiffness, Normal Modes, Crashworthiness)

3. Prepare Detailed FEA Models

4. Cost Model

Design 3GAHSS Assemblies:

1. Design CAD Data

2. Integrate 3GAHSS Assemblies into body structure CAD models

3. Prepare Detailed FEA Models of body structure (LS-DYNA, NASTRAN)

4. Assess Performance and Optimize Design, using 3G (gauge grade and geometry)

optimization, taking advantage of increased formability of 3GAHSS

5. Cost Model

6. Final Report

EDAG - Statement of Work


Baseline Vehicle & Assembly Body-side

1. Chosen Body Structure: 2008 Mid Size

sedan, CAD data provided by GM

2. Several important joints and major load

paths (important for stiffness and crash load

cases)

3. LWB One Piece Body side inner

4. Several reinforcements in joints and

members

5. LH & RH Body Side Assemblies – Mass

approx 100 kg (30% of BIW)


LSDYNA Model for Crash Performance

Crash Model System Masses

No Sub System Structure

Mass (kg)

1 BIW 331.6

2 Glass 26.2

3 BIW Adhesives 5.0

4 Door Front Left 28.7

5 Door Front Right 28.7

6 Door Rear Left 26.1

7 Door Rear Right 26.1

8 Rear Suspension 129.7

9 Front Suspension 157.8

10 Powertrain 296.1

11 Steering Column 22.3

12 IP Beam 42.8

13 Front Seat Left 25.0

14 Front Seat Right 23.2

15 Hood 16.2

16 Deck Lid 20.0

17 Fuel tank 74.2

18 Radiator 37.9

19 Rear Bumper/Fascia 17.8

20 Rear Seat System 21.0

21 Occupants 140.0

22 Paint / Latches / Trims /Fenders 93.4

TOTAL 1589.8

Subsystem

represented as

nodal masses

(purple spots) ,

constraint with

interpolation

constraints (blue

webs)

Vehicle COG

X 2827.7

Y 20.4

Z 514.5


Typical Crash System Model.

All subsystems represented

For the ICME study other sub-systems are represented by

lumped mass only (i.e., sub-system structures are NOT

included in the CAE model). The speed is LOWERED to

reduce the crash energy to achieve body structure intrusions

of similar magnitude of typical Mid-Size Sedan vehicle Pole Impact Speed 20mph

Pole Impact Speed 16.7mph

LSDYNA – Modeling Considerations

For crash load cases, initial velocities are reduced so that the new internal energy is 70% of the total internal

energy using standard regulation velocities. This is because the model is for a BIW only (i.e., not a full vehicle

system model). The 30% energy reduction is a judgment based on experience with prior projects.


16.7 mph

FMVSS214 – Pole Impact

-30%

Target numbers:

• B-Pillar Velocity & Intrusion

• Roof Rail / Rocker Intrusion at Impact 20 mph


Baseline Performance Results set as Targets

CAE Load Cases

1. Side Barrier

2. Side Pole

3. Front Impact

4. Rear Impact

5. Roof Crush

1. Body Static Stiffness (Torsion /

Bending)

2. Body Normal Vibration Modes


Body Side Assembly – design iter-3

Rocker Rear Joint:

Two Stamped Parts

Rocker Front Joint:

Four Stamped Parts

Max. mass saving while meeting crash performance, by

substituting 3GAHSS properties

Min. gauge assumed 0.6 mm

Body inner – two

thickness Laser

Welded Blank


Body Side Assembly – design iter-6

Replace 2 Parts with a

Single Laser Welded

Blank Stamping

Rocker Front Joint:

Replace 4 parts with 2

Laser Welded Blank

Stampings

Rocker Rear Joint:

Improved joint – iter-4

Rocker Front Joint:

Improved joint – iter-5 LWB – iter-6

Increase joint stiffness by removal of panel joints

Take advantage of increased formability of 3GAHSS


Iter-3 and Iter-6 Performance

Design Iteration #3 (Gauge

Reduction) Max. mass saving while meeting crash

performance, by substituting 3GAHSS

properties

Min. gauge assumed 0.6 mm

Design Iteration #6 (Combined

parts) Rocker inner combined parts to increase

joint stiffness


LSOPT Setup for iter-7

Gauge optimization of all parts in

side assembly, sensitivity analysis


Change in Stiffness per Kg change in Mass


LS-OPT Setup for iter-8 (from iter-7)

Geometry optimization


Geometry Optimization Setup • Focusing on 4 areas

− B-Pillar Reinforcement

− A-Pillar Reinforcement

− Inner Rocker

− Outer Rocker

• Will not change outer styling or reduce packaging space


Results for iter-9 Iter-9 results –

1. Meet all performance targets

2. Further mass saving limited by

stiffness

3. Superior crash performance due

to higher strength of 3GAHSS


Final 3G Optimization - NREL • Objective

− Mass Optimization

• Constraint

− Baseline crash and NVH targets

• Variables

− 62 Morphing points , 32 Thickness

variables, 32 Material Variables

• Job time estimate for EDAG cluster (480 CPU)

− 4.2 month @ 100% cluster utilization for

15 iterations, 189 designs per load-

case 19,845 runs for 15 iterations

• Software used

− LSOPT, LSDYNA -ICME (Explicit and

Implicit)

− Beta - ANSA ; www.ansa-usa.com

http://www.ansa-usa.com/




• CAE 3G Optimization required several ‘scripts’ for

running on the HPC – Peregrine, to transport data

between EDAG & HPC

• Proposed number of cores based on wall clock time

• Option 3 was approved to run on Peregrine HSC at

NREL

NREL HPC Setup

https://www.nrel.gov/esif/labs-hpc.html





Optimization Variable Setup for 3G Optimization

• 64 parts total

• Thickness

• Min = 0.55mm

• Max = 2.0mm

• Material*

• 10% Mn Steel

• 3% Mn Steel

• Geometry

• Rocker

• B-Pillar

• A-Pillar


Optimization Performance

315

318

321

324

327

330

333

0 1 2 3 4 5 6 7 8 9 10

BIW

Ma

ss (

kg)

Cycle #

70.8 kg – iter9 (LSOPT

baseline)

67.5 kg – optimized mass

Body side assembly

mass


Final Optimized Model

Final Model –

1. Design update based on

CAE optimization results,

2. MAT24 replaced with

ICME User Defined

3. Single step forming

4. Manual gauge adjustment

to increase mass saving


Rocker Profile Animation

Top View Baseline

Optimized


Process Driven - Technical Cost Modeling

What it is:

— An objective way to compare technologies, designs or manufacturing methods

— An analysis of manufacturing, equipment, tooling, labor, material, and energy costs

— A process to identify cost drivers

— A method to integrate piece cost, tooling cost and capital investment.

What it isn’t: — A precise method to obtain commercial price — A business case — An analysis of non-manufacturing overhead, such as prototype costs, logistics,

engineering and development costs

ICME Project Specific Assumption

The cost estimates used are not specific to any OEM and are based on industry

estimates. Specific OEMs will have varying estimates that include (but not limited to)

manufacturing flexibility, safety safe-guards, regional impacts, and vehicle variant

manufacturing strategy etc.


Baseline - Body Side Assembly LH Sequence

Body Side Asm LH

Assembly layout used to determine assembly

costs based on:

• Number of assembly stations

• Number of spot welding robots

• Complexity of assembly station

• Assembly cycle time

• Foot print of assembly station

• Labor requirements per assembly station


3GAHSS Cost Estimate per kg Grade HDG Visible

Tailor

Rolled

Coil

Tubes

Straight

as

shipped

Multiwall

Tube

Blank

Min t Max tPremium

($/kg)

Premium

($/kg)

Premium

($/kg)

Premium

($/kg)

Premium

($/kg)

Premium

($/kg)

1 Mild 140/270 0.35 4.60 0.82 0.00 0.06 0.05 0.55 0.25 0.65 1.0 1.0 1.0

2 BH 210/340 0.45 3.40 0.05 0.06 0.10 0.55 0.25 0.65 1.05 0.95 1.05

3 BH 260/370 0.45 2.80 0.05 0.06 0.10 0.55 0.25 0.65 1.05 0.95 1.05

4 BH 280/400 0.45 2.80 0.07 0.06 0.10 0.55 0.30 1.10 1.05 0.95 1.05

5 IF 260/410 0.40 2.30 0.07 0.00 0.10 0.55 0.30 0.70 1.05 0.95 1.05

6 IF 300/420 0.50 2.50 0.10 0.00 0.10 0.55 0.30 1.10 1.05 0.95 1.05

7 HSLA 350/450 0.50 5.00 0.12 0.10 NA 0.55 0.30 1.50 1.05 0.95 1.05

8 HSLA 420/500 0.60 5.00 0.14 0.10 NA 0.55 0.45 1.25 1.10 0.90 1.10

9 HSLA 490/600 0.60 5.00 0.16 0.10 NA 0.55 0.45 1.65 1.10 0.90 1.10

10 HSLA 550/650 0.60 5.00 0.35 0.10 NA 0.55 0.45 1.65 1.10 0.90 1.10

11 HSLA 700/780 2.00 5.00 - - - - - - - - -

12 SF 570/640 2.90 5.00 0.35 0.10 NA NA 0.45 2.05 1.10 0.90 1.10

13 SF 600/780 2.00 5.00 0.35 0.10 NA NA 0.45 2.05 1.10 0.90 1.10

14 TRIP 350/600 0.60 4.00 0.40 0.10 NA NA 0.45 1.25 1.10 0.90 1.10

15 TRIP 400/700 0.60 4.00 0.45 0.10 NA NA 0.45 1.65 1.10 0.90 1.10

16 TRIP 450/800 0.60 2.20 0.50 0.10 NA NA 0.50 1.30 1.15 0.85 1.15

17 TRIP 600/980 0.90 2.00 0.55 0.10 NA NA 0.55 1.35 1.15 0.85 1.15

18 FB 330/450 1.60 5.00 0.20 0.10 NA 0.55 0.30 1.10 1.05 0.95 1.05

19 FB 450/600 1.40 6.00 0.25 0.10 NA 0.55 0.45 1.65 1.10 0.90 1.10

20 DP 300/500 0.50 2.50 0.20 0.10 0.10 0.55 0.45 0.85 1.10 0.90 1.10

21 DP 350/600 0.60 5.00 0.26 0.10 0.10 0.55 0.45 1.25 1.10 0.90 1.10

22 DP 500/800 0.60 4.00 0.31 0.10 NA 0.55 0.50 0.90 1.15 0.85 1.15

23 DP 700/1000 0.60 2.30 0.38 0.10 NA NA 0.55 0.95 1.15 0.85 1.15

24 DP 800/1180 1.00 2.00 - - - - - - - - -

25 DP 1150/1270 0.60 2.00 0.38 0.10 NA NA 0.55 0.95 1.15 0.85 1.15

26 CP 500/800 0.80 4.00 0.31 0.10 NA NA 0.50 1.30 1.15 0.85 1.15

27 CP 600/900 1.00 4.00 0.35 0.10 NA NA 0.52 1.32 1.15 0.85 1.15

28 CP 750/900 1.60 4.00 0.40 0.10 NA NA 0.52 1.32 1.15 0.85 1.15

29 CP 800/1000 0.80 3.00 0.45 0.10 NA NA 0.55 1.35 1.15 0.85 1.15

30 CP 1000/1200 0.80 2.30 0.47 0.10 NA NA 0.60 1.40 1.20 0.80 1.20

31 CP 1050/1470 1.00 2.00 0.47 0.10 NA NA 0.60 1.80 1.20 0.80 1.20

32 MS 950/1200 0.50 3.20 0.47 NA NA NA 0.60 1.00 1.20 0.80 1.20

33 MS 1150/1400 0.50 2.00 0.48 NA NA NA 0.60 1.40 1.20 0.80 1.20

34 TWIP 500/980 0.80 2.00 1.20 0.10 NA NA 0.60 1.80 1.20 0.80 1.20

35 MS 1250/1500 0.50 2.00 0.51 0.10 NA NA 0.65 1.05 1.20 0.80 1.20

36 HF 1050/1500 (22MnB5) 0.60 4.50 0.75 NA NA 0.55 0.65 1.05 1.20 0.80 1.20

37 10Mn 980 0.60 3.00 0.65 0.10 0.60 1.20 0.80 1.20

38 3Mn 1500 0.60 3.00 0.53 0.10 0.60 1.20 0.80 1.20

Reference: Cold Rolled Mild 140/270

US Spot Midwest Market Price (Avg 2010-2014) (Source:

Platts. www.platts.com)

Reject

Rate

Factor

Item # Steel Grade

Ref

Material

Price

($/kg)

Thickness (mm) Tool

Investmt

Factor

Line

Rate

Factor

The average cost over 5 years (2010-2014) per kg of

steel used in the cost model for cold rolled (CR) mild

steel for the US market, published by PLATTS

(www.platts.com).

http://www.platts.com/


3GAHSS Cost Estimate per kg

$0.30

$0.40

$0.50

$0.60

$0.70

400 600 800 1000 1200

TRIP Cost

$0.30

$0.35

$0.40

$0.45

$0.50

$0.55

400 600 800 1000 1200 1400

Complex Phase Cost

Premium

Delta cost

estimate for:

10Mn - $0.65/kg

3Mn - $0.53/kg

Steel Grade UTS MPa

Delta ($/kg)

TRIP 350/600 600 $ 0.40

TRIP 400/700 700 $ 0.45

TRIP 450/800 800 $ 0.50

TRIP 600/980 980 $ 0.55

TRIP X/1200 1200 $ 0.65

Steel Grade UTS MPa

Delta ($/kg)

CP 500/800 600 $ 0.31

CP 600/900 700 $ 0.35

CP 750/900 800 $ 0.40

CP 800/1000 980 $ 0.45

CP 1000/1200 1200 $ 0.47

CP 1050/1470 1470 $ 0.47

CP 1500 1500 $ 0.53


Vehicle System System Definition (1)

Weight

Reduction

Target (2)

Cost per Pound of

Weight Saved ($/lb

saved) (2)

Additional Requirements

Body Body-in-White, Closures, Windows,

Fenders, & Bumpers ≥35% ≤$3.18/lb Replacement Technology

must achieve Function and

Packaging Requirements of

Technology to be Replaced Chassis Suspension, Steering, Wheels, &

Underbody Structural Components ≥25% ≤$3.11/lb

Note (2): When compared to a 2006 or Later Production Light Duty Vehicle Technologies.

• Baseline Design: 94.6 kg.

• 3GAHSS Design: 66.7 kg.

• Mass savings: 27.9 Kg. (-30%)

• Parts reduced from 46 to 28

• Cost increase $ 20.90

• Cost per Pound of Weight Saved

$0.32 / lb ($0.70 / kg)

$0.32/lb

$1.26/lb

Accomplishments


Future (2025) Class Average Weights

EDAG Mass Saving Estimates

2015 Ford F-

150

Approximate Fuel

saving due to

Lightweighting

10%


2015 Ford F-

150

Approximate Fuel

saving due to

Lightweighting

10%

Further development and availability of 3GAHSS will provide an

excellent economic path forward for meeting these goals

Future (2025) Class Average Weights

EDAG Mass Saving Estimates


Thank you

The material in this presentation was possible with a lot of good feed back

from all participants

Universities / National Labs Industry Consortiums

Brown University FCA US LLC Auto/Steel Partnership

Clemson University Ford Motor Company United States Automotive Materials Partnership

Colorado School of Mines General Motors Company

Pacific Northwest National Lab ArcelorMittal

Ohio State University AK Steel Corporation

University of Illinois at Urbana-Champaign Nucor Steel Corporation

EDAG

LSTC


Eric McCarty

Auto/Steel Partnership

1 (248) 520 3009

[email protected]

Questions?

Visit EDAG’s web site for more information:

http://www.edag.de/en/edag/stories/cocoon.html

Harry Singh

Director Lightweighting

1 (248) 635-3174

[email protected]

3D Printed EDAG LIGHT COCOON

mailto:[email protected]

http://www.edag.de/en/edag/stories/cocoon.html




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