Lightweighting and steel technologies in the all-new 2016 Chevrolet Malibu 2017 Buick LaCrosse

Transcription

1 Lightweighting and steel technologies in the all-new 2016 Chevrolet Malibu 2017 Buick LaCrosse v2 Terry A. Swartzell Underbody System Architect General Motors Company May 11, 2016

2 AGENDA The new sedans Mass reduction hierarchy Part sharing Steel technologies Crash examples

3 THE NEW SEDANS 2016 Chevrolet Malibu 9th generation 111 wheelbase Sold in 18 countries around the world 3 assembly sites (Fairfax, China, Korea) 2017 Buick LaCrosse 3 rd generation 114 wheelbase Sold in US, Canada and China 2 assembly sites (Detroit Hamtramck & China)

4 EFFICIENTLY POWERFUL All-New 1.5L Turbo 6-speed auto transmission 160 hp / 184 ft-lb of torque 2.0L Turbo 8-speed auto trans 250 hp / 258 ft-lb of torque 1.8L Hybrid 60 cell / 1.5 kwh Li-Ion battery Leverages Volt technology

5 2017 BUICK LACROSSE 3.6L V6 Quiet-Tuning Stronger, longer, stiffer & lighter

6 STRONGER, LONGER, STIFFER & LIGHTER 2016 Malibu BIW: ~331 kg* 2017 Lacrosse BIW: ~343 kg* 2.3 longer OAL vs predecessor 0.5 longer OAL vs predecessor 3.6 longer W/B vs predecessor 2.7 longer W/B vs predecessor Body structure ~ 100 lbs lighter than previous generation (Vehicle ~ 300 lbs lighter) * BIW structure, paint, sealer, adhesive, bolt-on braces, etc

7 GM S BODY MASS REDUCTION HIERARCHY Higher Control of architectural bandwidth Influence on body mass Lower kg Efficient integration of systems Aggressive CAE iteration & optimization The right performance targets Efficient design fundamentals The right steel grades Execution excellence (short flanges, scallops, lightening holes, etc)

8 GM S BODY MASS REDUCTION HIERARCHY Control of architectural bandwidth Efficient integration of systems Aggressive CAE iteration & optimization The right performance targets Efficient design fundamentals The right steel grades Execution excellence (short flanges, scallops, lightening holes, etc)

9 ARCHITECTURE BANDWIDTH GM OLD APPROACH: ONE UNDERBODY FITS ALL Possible future derivatives & variants GVM (kg) 2016 FWD Malibu LaCrosse AWD long W/B Scar Mass Illustrative only not to scale Possible future Derivatives and variants (Bubble size indicates global volume)

10 ARCHITECTURE BANDWIDTH GM NEW APPROACH: MANAGED BANDWIDTH GVM (kg) High volume low mass optimization point LaCrosse AWD long W/B Possible future derivatives & variants 2016 FWD Malibu Higher mass optimization point Illustrative only not to scale Possible future Derivatives and variants (Bubble size indicates global volume)

11 ARCHITECTURE BANDWIDTH Low mass optimization point Higher mass optimization point 2016 Malibu optimized for: 2017 Lacrosse optimized for: 4 cylinder only FWD only Base FWD tunnel Base W/B 4-link rear suspension Base strut front suspension Lower GVM s Minimum scar mass V6 engine FWD & AWD Larger AWD tunnel Longer W/B & ROH 5-link rear suspension HiPer strut front suspension Higher GVM s

12 BODY STRUCTURE SHARING STRATEGY COMMON SOLUTIONS UNIQUE PARTS Low mass optimization point 2016 Chevrolet Malibu Higher mass optimization point 2017 Buick LaCrosse (NA) Malibu base parts Common w/malibu Trim change only Unique to LaCrosse

13 GM S BODY MASS REDUCTION HIERARCHY Control of architectural bandwidth Efficient integration of systems Aggressive CAE iteration & optimization The right performance targets Efficient design fundamentals The right steel grades Execution excellence (short flanges, scallops, lightening holes, etc)

14 AGGRESSIVE VIRTUAL DEVELOPMENT Optimization iterations 6 virtual gates per model 2832 standard loadcases 10 million CPU hours Visualization & interpretation iterations Concept design iterations

15 FULLY OPTIMIZED FINAL ITERATION 1 Extended seatback beam 2 Planar & parallel faces 3 Multi-piece gusset 4 Integrated right-sized sections Max Ixx Upper seatback section

16 RESULTS: STIFFER PERFORMANCE Global Static Torsion (kn-m/deg) Predecessor Malibu New Malibu Base roof: 23.0 Sunroof: % +9%

17 HIGH EFFICIENCY FRONT TOPOLOGY CONCEPTS 1 Strut tower - A pillar loadpath 2 Stiff powertrain mount loadpaths 3 Hoop structure between struts 5 Upper rail flows into cradle standoff 4 Drag section tubes & stampings

18 PERFORMANCE RESULTS: STIFF CONTINUOUS HIGH QUALITY DEFORMED MODES Unit load 5 Upper rail flow into cradle standoff

19 N&V IS KEY DRIVER OF TOPOLOGY Receiver Cabin noise and vibration Path Structure Source Powertrain and road 1 Example: Cradle mount dynamic stiffness development. 2 Example: engine pulse response optimization Structure Goals: 1 Maximize mount isolation. 2 Minimize vibration sensitivity.

20 GM S BODY MASS REDUCTION HIERARCHY Control of architectural bandwidth Efficient integration of systems Aggressive CAE iteration & optimization The right performance targets Efficient design fundamentals The right steel grades Execution excellence (short flanges, scallops, lightening holes, etc)

21 EFFICIENT DESIGN FUNDAMENTALS Thin skins Stable sections Bulkheads Local reinforcement Bolt-in struts

22 EFFICIENT FUNDAMENTALS EXAMPLE BOLT-IN N&V STIFFENER Achieves key target for dynamic stiffness Low mass - very effective Allows lean down-rigger structure Unit load

23 EFFICIENT DESIGN FUNDAMENTALS 54 meters of structure adhesive Supplements spot welds Improved durability at thin gauges Enhances stiffness Arc welding/brazing Used in high value areas Allows single sided joining Allows smaller, stiffer sub-assemblies

24 GM S BODY MASS RED N HIERARCHY Control of architectural bandwidth Efficient integration of systems Aggressive CAE iteration & optimization The right performance targets Efficient design fundamentals The right steel grades Execution excellence (short flanges, scallops, lightening holes, etc)

25 THE RIGHT STEEL GRADES Bake hardenable Dual phase & multi-phase HSLA 24% 34% 9% 27% Mild 7% PHS & martensite

26 HIGH THICKNESS ONLY WHERE REQUIRED Variable thickness blank Thicker at max bending moment Thickness profile* transitions Long thickness transitions Thin Thick Thin Side view of part * Thickness profile optimized for Malibu. Reinforcement added for higher GVM LaCrosse.

27 HIGH THICKNESS ONLY WHERE REQUIRED Co-formed dash & constrained layer doubler Co-formed patch blank utilization Steel-viscoelastic-steel sandwich in key N&V area Net vehicle mass savings (lower acoustic mass) Co-formed PHS B-pillar and reinforcement PHS patch on PHS pillar Avoids dimensional issues Maximizes weld flats

28 HIGH THICKNESS ONLY WHERE REQUIRED Front rail reinf ````` Varying thickness Front rail outer Varying thickness & grade Laser welded rail blanks Front rail inner Varying thickness & grade Front rail rear extension ``` Varying thickness & grade Rear rail lower ``` Varying thickness & grade

29 LASER WELDED RAIL BLANK TUNING EXAMPLE Crush Fold Backup Zone A Zone B Zone C Example: China NCAP rigid moving barrier Gauge and grade in each zone optimized for performance

30 CRASH EXAMPLE

31 SMALL OVERLAP PERFORMANCE Vehicle deflection Bolt-on body parts Cradle deflector Strong back-up structure High part strength High weld strength

32 SMALL OVERLAP ANALYTICAL DEFORMATION Vehicle Deflection Strong backup structure

33 THANK YOU FOR YOUR ATTENTION!