Overcoming the all-steelbody Structure: Materials
for Light Weight
Construction.
Clovis Zapata
Research Associate
BRASS
Cardiff University
Presentation Structure
1 - Lightweight necessity in automotive
design and construction.
2 – Value X Weight
3 - The all-steel-body Structure
4 – Lean weight importance
5 – Cost Modelling exercise with alternative
materials to the all-steel-body structure
1. Lightweight necessity
The environmental impact of the
automobile is well known (life cycle).
Several environmental regulations have
been imposed to try to correct market
failures. (e.g. Emissions regulations, Endof-Life Vehicle Directive and etc.)
1. Lightweight necessity
Fuel economy has gained a dramatic
importance
A reduction of 100 kilograms in the body
weight reduces fuel consumption by
approximately 0.5 litres per 100
kilometres.
Each litre of gasoline saved reduces CO2
emissions by approximately 24 grams per
kilometre.
“I cannot imagine where the delusion that weight
means strength came from… In transportation
why put extra weight in a machine? Fat men
cannot run as fast as thin men but we build most
of our vehicles as though dead-weight fat
increased speed! …
Some day we shall discover how further to
eliminate weight. Take wood, for example. For
certain purposes wood is now the best
substance we know, but wood is extremely
wasteful. The wood in a Ford car contains thirty
pounds of water. There must be some way of
doing better than that “
Henry Ford, My Life and Work.
1.Lightweight necessity
Vehicles are becoming larger and heavier.
Luxury, safety and electrical equipments
have been added to the standard vehicles.
The addition of the Sport-Utility Vehicles –
SUVs, 4x4’s.
Fuel economy is different from fuel
efficiency.
1. Lightweight necessity
Cars are getting
heavier and bigger
every new generation.
Every year the
average weight of
vehicles increases by
35 lbs (16kilos).
1. Lightweight necessity
Medium sized vehicles are almost twice as heavy as
20 years ago.
Volkswagen Golf
1976
Golf GTI MKI (820kgs)
108 hp
2006
Golf GTI MKV (1340kg)
200hp
Polo (1194Kg)
Fox (1100kg)
Vicious cycle of weight
Customer increasing
Demands:
1 – Safety
2 – Performance
3 - Luxury
Higher Car body
rigidity
More powerful
engine
Package
Adaptation
(Larger fuel tank
Larger breaks,
etc)
Heavier
Structure
result :each new
generation
is heavier
2. Value X Weight
From the manufacturers point of view,
adding weight is a way to add value - to
make cars bigger and more comfortable
and more powerful and raise the profit
margins.
“Small-vehicles – small profits”.
We argue that to add value the increase in
weight must not occur.
2. Value X Weight
Relationship between value and price for new vehicles sold in the UK
PPW
Price
Per
Weight
Positive relationship
PPP=23.4 + 1/100CP
Outliers not present
Car Price
Car price per kg increases with vehicle weight.
2. Value X Weight
For the manufacturers, reducing the
content of cheap (heavy ) materials
releases the opportunity for greater valueadded PPW applications which the
consumer pays for . (e.g. Satellite
Navigation, etc).
2. Value X Weight
From the consumer point of view, there is an
established cultural belief that weight tends to be
associated with safety and quality.
Are SUV’s really safer to the driver ?
What about to other drivers and pedestrians ?
3. All-steel body structure
High sunk costs in plants and models
which lead to high risk operations;
Over-supply;
Long delivery time;
Inflexibility of manufacturing;
High Break even points (250,000).
4. Lean Weight importance
enhanced fuel consumption;
improvements in vehicle performance ;
and a smaller vehicle also needs smaller
mechanical parts including engine, brakes,
gear box, and other mechanical and
structural parts.
Weight saving in the structure of the
vehicle can be substituted by other luxury
or safety accessories.
4. Lean Weight importance
“A designer knows he has achieved
perfection not when there is nothing
left to add, but when there is nothing
more to take away”
Antoine de Saint-Exupéry
4. Lean Weight importance
Reduced Vehicle
Weight
Lightweight
Materials
•Unreinforced and
reinforced Plastics
•Aluminium, Magnesium
•High Strength Steels
Structural
lightweight
Construction
•New structures and
complex geometries
Optimizing of
Production Process
•Light joining techniques
•New manufacturing
processes
(Hydroforming)
5. Cost Modelling exercise
To cost a compact vehicle using different
materials.
Comparison was made in the Body-in –
White Structure to contrast traditional allsteel body structure to alternative
materials.
Micro-Factory retailing model was used.
Model assumptions
(in £ Millions)
Sunk Costs
Traditional
Plant
Model R&D
Model Tooling
1,500
500
500
Alternative
(MFR)
50
100
250
Comparison of Parts Weight
Carbon
92.3
F Glass
Comp
Al
Steel
152
189
Kg
Preliminary Results
Cost Comparison: Steel X Alternative Materials
Unit
Cost
£’s
(x1000)
Carbon
Comp
Steel
3
132
165
Carb – AeroStable Carbon Car.
Aluminium is not included
Total Volume
(x1000)
Future Research
Further develop the model (Case studies);
Analysis of sustainable strategic
opportunities in the context of the MicroFactory Retailing;
Evaluation of the economic feasibility of a
new market entrant using the micro-factory
retailing model.
Conclusion
The issue of weight is likely to become more
important to manufacturers and customers due
to fuel economy.
The economic feasibility of producing vehicles
with alternative materials has not yet been
completely addressed (following Micro-Factory
Retailing parameters).
Consumers may not abandon large vehicles.
The shift away form heavy cars can only came
from alternative materials.
Weight reduction involves all materials and
components suppliers.