Download - Lecture 9, Global Lightweighting
-
BY
Dr. M. Nasim [email protected]
734 546 0450
Lecture IXMarch 13, 2014
Introduction to Vehicle Design: Materials &
Manufacturing I
-
Forces Acting On a Two-Axle Vehicle
-
Normal Loads on Axles
Normal Load on Front Axle, Wr
Wf = (Wl2cos Raha haw/g Rdhd whsin)/L
The negative sign for the term whsin vehicle is climbing
up!
Normal Load on Rear Axle, Wr
Wr = (Wl1cos + Raha+ haw/g + Rdhd whsin)/L
The positive sign for the term whsin vehicle is climbing
up!
-
Material Percentage of vehicle weight Major areas of application
Steel 55 Body structure, body panels, engine and transmission components,
suspension components, driveline
components
Cast iron 9 Engine components, brakes, suspension
Aluminum 9 Body Panels, Engine block, wheel
Copper 1.5 Wiring, electrical components
Polymers (plastics)
and polymer matrix
composites
9 Interior components, electrical and
electronic components, under-the
hood components, fuel line
components
Elastomers 4 Tires, trims, gaskets
Glass 3 Glazing
Other 10 Carpets, fluids, lubricants, etc.
Material Distributions in Typical Automobiles
-
Lightweighting Strategy
Outline
OE Customer FocusEfficient Fundamentals
Vehicles
Camaro Z28Opel AdamSilveradoCadillac ATSChevrolet SSCadillac CTSCorvette
Technologies
SteelAluminumCarbon Fiber CompositesMagnesiumShape Memory AlloysJoining
-
Lightweighting Strategy
-
Efficient Fundamentals Premium Matls & Mfg Processes
Body Lightweighting Strategy
CostUp CFRP + Aluminum +
Baseline5%0%
Regression Line
CostDown
(Applied Independent of Material
type to Minimize Mass & Cost)
PHS + Aluminum
AHSS/UHSS/PHS
Magnesium
MaterialMaterial Utilization
Customer Selection
Requirements
10% 20% 30% 40%
Percent Below Industry
-
Customer Focus
-
Customer Focus
Means understand what the customer is expects.
Delivering a vehicle that exceeds expectations
Vehicle must be priced / sized consistent with competition
-
Camaro Z28
-
Understanding the Customer
To increase speed, Chevrolet jettisoned just about everythingthat added weight but wasn't critical. That includes carpeting in
the trunk, insulation and every speaker but one.
Vehicle mass reduced by 140 kg.
-
Efficient Fundamentals
-
Efficient Fundamentals
Overall right sizing
Topology Optimization
Material Selection
Gage Selection
Material Utilization
Independent of material type vehicle platform
-
Efficient Fundamentals Premium Matls & Mfg Processes
Body Lightweighting Strategy
CostUp
AHSS/UHSS/PHS
Baseline5%0%
Regression Line
CostDown
(Applied Independent of Material
type to Minimize Mass & Cost)
AHSS/UHSS/
MaterialMaterial Utilization
Customer Selection
Requirements
10% 20% 30% 40%
Percent Below Industry
-
Opel ADAM
-
56,3 %16,5 % 16,5 %
% %
Opel Adam Materials Mild SteelsBH &
HSS DP
PHS
AL
8,4 1,6
-
HS
Opel
HB3
Adam Materials
AdamCorsa
1.7 MM PHS 1.3 MM P
1.0 MM
PATCH
PHS
WEIGHT = 2.9KG
WEIGHT = 4.3KG
-
Zinc-coatedPHS Rear Rails
CORSA HB3CR340
t=2,2mm / 5,72kg
WEIGHT = 5.72KGADAM
PHS
t =1,9mm
3,42kg WEIGHT = 4.4KG
DP800
t=1,7mm
0,98kg
-
Silverado
-
ATS
-
ATS Materials Strategy
-
Cadillac Steel Strength Trend
Tensile strength (average MPa)
429371
337
2003 Predecessor 2008 Predecessor 2013 ATS
-
el
ATS Material Utilization
2.8 kgiminated
-
Patch Laminated Dash
-
Efficient Fundamentals Premium Matls & Mfg Processes
Body LightweightingStrategy
CostUp
Baseline5%0%
Regression Line
CostDown
(Applied Independent of Material
type to Minimize Mass & Cost)
PHS + Aluminum
MaterialMaterial Utilization
Customer Selection
Requirements
10% 20% 30% 40%
Percent Below Industry
-
Aluminum
-
Chevy SS
-
CTS
-
CTS Door-in-White
General Motors first aluminum doorstructure, saving ~18kg/vehiclefrom the most mass efficient steeldoor systems in the industry, and~25kg/vehicle from the Gen 2 CTS
Includes additional noise absorptioncontent to achieve Library Quietperformance
-
12.0
8.0
0.60 0.65 0.70 0
Cadillac CTS Door Benchmarking
24.0
R = 0.6196
InfinitEff
More Efficient
Efficiency: 0.73.75 0.80 0.85 0.90 0.95 1.00 1.05
DIW
Sp
ecif
icM
ass
(kg
)
Front DIW Mass Prediction
22.0
20.0
18.0
16.0
14.0
Less Efficient y = 17.658x + 3.5464
y = 18.803x + 0.8224R = 0.8657
5.0 kg below Mass Efficient Steel
Prediction
BMW 7 Series: 11.0 kgEfficiency: 0.71
InfinitEff
i M45: 11.0 kgiciency: 0.73
More Effici
CTS: 10.7 kgEfficiency: 0.68
10.0
BMW535iL: 10.8 kg
~Surface Area Below Belt (m^2)
-
ATS Aluminum HPDC Shock Towers
-
Corvette Stingray
-
Aluminum Frame
-
Efficient Fundamentals Premium Matls & Mfg Processes
Body Lightweighting Strategy
Aluminum + CFRP +CostUp
(Applied Independent of Material
Magnesium
Baseline5%0%
Regression Line
CostDown
(Applied Independent of Material
type to Minimize Mass & Cost)
MaterialMaterial Utilization
Customer Selection
Requirements
10% 20% 30% 40%
Percent Below Industry
-
Carbon Fiber Composites
-
Leader on panel volumeGM Carbon Fiber Leadership
Industry Not purely mass driven executions Design is not optimized for CF; Material substitution for SMC
Z06 Z07Fenders
Hood
Roof Outer Panel
Fascia Splitter
Rocker Panels
Floor Pan Assemblies
ZR1Fenders
Hood
Roof Outer Panel (exposed)
Fascia Splitter (exposed)Fenders
Rocker Panels (exposed)
Roof Bow Cover (exposed)Wheel House Outer Panel
-
Corvette Stingray Carbon Fiber Hood
-
Magnesium
-
Magnesiumon Corvette
Steering Column Support Seats
-
Magnesium Sheet Prototypes at GM
-
Hot ToolForm Press Cleaning Robot
Form Tool Opera
Statio
Ergono
Destack Robot
Exit
Convey
Cooling Fixture
Location
Press Automation
Blank Pre-Heater
Blank Presentation
Fixture
Blank Stack
ance
tor n& mics
GMs QPF Process
Hot blow forming at automotive volumes
Blank Stack
Blank Presentation
Fixture
Blank Pre-Heater
Press Automation
Cooling Fixture
Location
Exit
Conveyance
Destack Robot
Operator Station &
Ergonomics
Form Tool
Form PressHot Tool
Cleaning Robot
-
QPF Aluminum
-
Prototype Magnesium Intensive Door
(Inner, STAR panel, Beltline reinforcement)
-
Magnesium SUV Door Inner and Liftgate Inner
-
Magnesium Hood Inner and Outer
-
GM Hood Assembly
54
-
Decklid for Cadillac STS
AluminumOuter panelAluminum
Hinge reinf .
Magnesium
AluminumLatch reinf .
-
CAE Predictions
Peak stress locations
Overslam deflection
Al MgAZ31
Inner panel thickness 1.6 mm
(% of max allowed) 86.00 84.00
Inner panel thickness 0.8 mm
(% of max allowed) 92.00 102.00
Peak von Mises Stress
Al MgAZ31
Inner panel thickness 1.6 mm
(max stress as a fraction of
yield strength)1.16 0.98
Inner panel thickness 0.8 mm
(max stress as a fraction of
yield strength)1.16 1.04
-
As-Formed Panels
-
Trimmed Inner Panel(Die Trimmed)
3.6 kg in 1.6 mm AA5083 Al sheet2.4 kg in 1.6 mm AZ31B Mg sheet
-
Assembly Cell with Coated Inner Panel
-
Joining
Rivet reinforcements to inners instead of clinch
-
Assembled Panels with Mg Inners
-
Drop Tower Testing of Mg Decklid
Before After
-
Hem Corrosion Protection Details
(Sheared Edge Preparation Patent Pending)
Rounding of the cut edge is key to achieving uniform coating thickness
and good corrosion resistance.
AZ31
Powder coating
Uniform powder coating thickness on rounded edge
Thin coating at sharp corner onsheared edge
-
Additional Lightweight Technology
Developments
Aluminum Spot Welding
Shape Memory Alloys
-
GM Al RSW ApplicationHistory
GM Electric Vehicle, EV1 (1996) Manually weld bonded structure with
coating
GMT800 SUV high volume Al liftgate (1999) MaleCap High volume conventional MFDC RSW using
Ford-style male cap
QPF mule structure (2001-2002) Prototype structures built with grit blasted
electrodes (U.S. #6,861,609)
UniversalElectrode
MRD Electrode Arlington GMT920 liftgate (2008) 1st application of MRD electrode (U.S.
#8,222,560)
CTS-V Hood (2008) 2nd application of MRD electrode
-
Corvette Welding
Y1XX Corvette StructuralComponents (2013)
Heavy sheet, extrusions, andcastings
General Motors
MRD Electrode
-
SMA Potential Aero Applications
Air dam
Louver
-
Active Air Dam
-
Summary
GM has a comprehensive lightweighting strategy thatfocuses on a combination of efficient designfundamentals and the strategic use of premiummaterials including AHSS, PHS, Aluminum, CarbonFiber Composites, and Magnesium.
Numerous recent technology demonstrations have provided excellent opportunities to demonstrate elements of GMs strategy.