New Frontiers in Light MetalsNew Frontiers
organised by Delft University of Technology and Eindhoven
University of Technology
Held at the Auditorium of the Eindhoven University of
Technology
Eindhoven, the Netherlands on 23-25 June 2010
Edited by
Delft University of Technology Mekelweg 2, 2628CD, Delft, the
Netherlands
and
Prof. Frans Soetens Department of Architecture, Building and
Planning
Eindhoven University of Technology Den Dolech 2, 5612 AZ Eindhoven,
the Netherlands
www.inalco2010.com
The INALCO 2010 Conference “New Frontiers in Light Metals” has been
organised by the
Department of Materials Science and Engineering, Delft University
of Technology and the
Department of Architecture, Building and Planning of Eindhoven
University of Technology.
Organising committee:
Prof. Laurens Katgerman, Delft University, Symposium Chairman
Prof. Frans Soetens, Eindhoven University, Symposium Chairman
Mr. Rein van de Velde, van de Velde Consultancy, Zevenhuizen,
Conference Secretary
Prof. Rob Boom, Corus Research & Development, IJmuiden
Mr. Frans Bijlhouwer MBA, Quality Consultants, Oudheusden
Dr. Dmitry Eskin, Materials innovation institute (M2i), Delft
Mrs. Dianne van Hove, Eindhoven University, Eindhoven
Dr. Johan Maljaars, TNO, Delft
Prof. Wim Poelman, Twente University, Enschede
Mr. Rudolf de Ruijter, de Ruijter Consultancy, Heerenveen,
Symposium Coordinator
Symposium organisation and coordination: de Ruijter Consultancy,
Heerenveen
Visual identity: Nienke Katgerman, Gront, Amsterdam
(www.gront.nl)
Lay-out: Van der Let & Partners Identity, Heerenveen
(www.vdlp.nl)
Print: Drukkerij Banda Heerenveen (www.banda.nl)
© 2010 The authors and IOS Press
All rights reserved. No part of this book may be reproduced, stored
in a retrieval system, or
transmitted, in any form or by any means, without prior written
permission from the publisher.
ISBN 978-1-60750-585-3 (print)
ISBN 978-1-60750-586-0 (online)
e-mail:
[email protected]
LEGAL NOTICE
The publisher is not responsible for the use which might be made of
the following information.
PRINTED IN THE NETHERLANDS
VV
Preface
The INALCO 2010 Conference “New Frontiers in Light Metals” is the
eleventh in a series
of aluminium conferences organised since 1979. It will consist of
keynote lectures by invited
speakers as well as oral presentations of papers submitted by
attendees.
The 1st International Conference of welded products and
constructions with aluminium
alloys was held at Cleveland, USA in 1979 and established as INALCO
at the 2nd conference
held in Munich, Germany in 1982. Since then these conferences have
been held every 3 years at
different locations all over the world.
With the 2010 INALCO Conference “New Frontiers in Light Metals” we
want to emphasize
the many challenges that face the industry today and the creative
and innovative solutions that
are developed by the industry and the research institutes to remain
competitive in the light metals
world that is becoming more global every year. We have also widened
the scope of the conference
by including contributions on magnesium technology.
The programme of the 3 day conference consists of two plenary
sessions and 12 parallel sessions.
The topics of the parallel sessions are:
In connection with the conference programme an exhibition of new
developments is organised.
Furthermore an excursion programme is added to the programme to
give exposure to interesting
aluminium applications in the Netherlands. The proceedings of
INALCO 2010 will be available
both on CD and in print at the start of the conference.
The symposium committee gratefully acknowledge the support of the
many sponsors
and exhibitors to make the symposium possible. As symposium
chairmen we would like to
acknowledge in particular Messrs Rein van de Velde and Rudolf de
Ruijter for their enthusiastic
support in planning and organising the conference. Also the
cooperation of the members of the
symposium committee has been very fruitful in identifying relevant
new technical areas and
potential contributors.
Finally I would like to gratefully acknowledge the speakers and
authors for their contributions
to make the symposium a success.
Prof. Laurens Katgerman Prof. Frans Soetens
Symposium Chairman Symposium Chairman
Department of Materials Science and Department of Architecture,
Building and
Engineering Planning
the Netherlands the Netherlands
11th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
VI
Prof. F.M. Mazzolani
Dr. S. Sato
Dr. P. Benson
Prof. M. Langseth
Dr. M.Z. Lokshin
Prof. Qi-Lin Zhang
Dr. S. Hoekstra
Mr. F. Kurvers
Dr. W. Loué
Novelis, Dudelange, Luxemburg
Dr. H.M.E. Miedema
Prof. W. Schneider
Mr. P. de Schrynmakers
Dr. M. H. Skillingberg
Prof. M. Waas
Prof. J. Westra
VII
Organisation
Aluminium, Architecture and Human Ecology 3
Michael Stacey Discovery Invention and Innovation of Friction
Technologies –
for the Aluminium Industries 13
W.M. Thomas, J. Martin and C.S. Wiesner Why does the European Car
Industry need Light Metals
to survive in a Sustainable World? 23
Mark White
Session leaders: Prof. Laurens Katgerman & Prof. Frans
Soetens
Developing Stability Design Criteria for Aluminum Structures
29
Ronald D. Ziemian and J. Randolph Kissell Will today’s Aluminium
Recycling Industry be the primary Industry of Tomorrow? 39
Frans Bijlhouwer MBA Aluminium in Façades 47
Ulrich Knaack Two Twin Aluminium Domes of the Enel Plant in
Civitavecchia (Italy) 57
Federico M. Mazzolani Creativity in Engineering of Aluminium
Structures 67
D. de Kluijver
Session leader: Prof. Frans Soetens
Laser Welding and Hybrid Welding of Aluminium Alloys 79
Seiji Katayama, Yousuke Kawahito and Masami Mizutani Weldability of
Al-Cu Alloy Sheet by Power Beam and FSW Processes 91
Michinori Okubo, Toshiyuki Hasegawa, Hitoshi Mitomi, Hideto Iida
and Naotaka Kamimura
IXIX
The Friction Welding Method with Translational Friction by
Intermediate Material 99
Ryoji Tsujino, Masaharu Hashimoto, Kiyoshi Matsuura and Kiyokazu
Roko Welding of Aluminum Casting Alloys 111
Masatoshi Enomoto
Session leader: Prof. Frans Soetens
Pull-Over of Washer-Head Screws in Moderately Thin Aluminum
117
James C. LaBelle, P.E., Doc.E. Experimental Research on pinned
Connections in Aluminium Truss Girders 129
B.W.E.M. van Hove and F. Soetens Finite Element Analysis of
Friction Stir Welding Affected
by Heat Conduction through the Welding Jig 139
Tetsuro Sato and Toshiyuki Suda Estimation of Transient Temperature
Distribution in Friction Welding Process
of Aluminum Alloys 147
ARCHITECTURE
The CAD-tool 2.0 morphological Scheme of non-orthogonal High-rises
159
Karel Vollers Aluminium and Double Skin Facades 177
Aneel Kilaire¹ and Philip Effective Section Calculating of
Aluminium Plate Assembly
under uniform Compression considering Interactive Local Buckling
189
Zhang Qilin, Tang Hailin, Wu Yage Experimental and numerical
Analyses of Aluminium Frames
exposed to Fire Conditions 201
J. Maljaars and F. Soetens
Architecture 2 213
The Sound of Silence,
high-tech Solution along the A2 near Eindhoven (Holland) 213
R.C.van Kemenade
Rajan Ambat and Manthana Jariyaboon 233
Lars Bouwman
MATERIALS TECHNOLOGY
Highlights of Collaboration between Industry and Academia
in the Area of Aluminium Metallurgy 243
Menno van der Winden, Cheng Liu, Démian Ruvalcabe-Jiminez, Lin
Zhuang Formability of heat treated Al-Mg-Si Alloys 251
Manoj Kumar, Cecilia Poletti and Hans Peter Degischer Correlation
between homogenization Treatment and recrystallization
Behavior
during hot Compression of AA7475 Aluminum Alloy 259
H. Ahmed, A. R. Eivani, J. Zhou and J. Duszczyk Effects of
Overburning on Microstructure and Mechanical Properties
of 2024 Aluminium Alloy and Ways and Means to avoid it 269
S. Akhtar
Materials Technology 2 - Casting 275
Session leader: Prof. Rob Boom
The Use of organic Coatings to prevent Molten Aluminium Water
Explosions 275
Alex W. Lowery, Joe Roberts 281
D.G. Eskin, T.V. Atamanenko, L. Zhang and L. Katgerman High
Strength Aluminium Investment casting at Zollern, using the Sophia
Process 289
Bernd Hornung The Effect of Reducing Molecular Weight of the Foam
Pattern on the
Porosity of al Alloy Castings in the Lost Foam Casting Process
295
K. Siavashi1, C. Topping2 and W. D.
Materials Technology 3 - Extrusion 303
Session leader: Frans Bijlhouwer
303
B. Eghtedari, M. Meratian, G. Aryanpour, M. Mohammadi An
Investigation of dynamic Recrystallization during hot Extrusion
of
Al-4.5Zn-1Mg Alloy 311
A.R. Eivani, A.J. den Bakker, J. Zhou and J. Duszczyk An Integrated
Approach for Predictive Control of Extrusion Weld Seams:
XIXI
Experimental Support 319
A.J. den Bakker, R.J. Werkhoven, W.H. Sillekens, and L. Katgerman
Magnesium Forging Technology: State-of-the-Art and Development
Perspectives 329
W.H. Sillekens, G. Kurz and R.J. Werkhoven
STRUCTURAL DESIGN
Session leader: Prof. Wallace Sanders
Experimental and numerical Studies on pure Aluminium Shear Panels
for
seismic Protection of framed Structures: an Overview 341
G. De Matteisa, G. Brandob and F.M. Mazzolani Distortional elastic
Buckling for Aluminium: Available Prediction Models
353
by N. Kutanova, T. Peköz, F. Soetens 363
M. Mensinger, R. Parra1, C. Radlbeck Mechanical Properties of
AA6082 welded Joints with Nd-YAG Laser 373
Seiji Sasabe and Tsuyoshi Matsumoto
Structural Design 2 - Research and applications 385
Session leader: Prof. Teoman Pekoz
385
F.M. Mazzolani, V. Piluso, G. Rizzano 397
O. R. van der Meulen; J. Maljaars; F. Soetens Dynamic Behaviour of
AA2024 under blast loading: Experiments and Simulations 409
J. Mediavilla Varas, F. Soetens, R. vd Meulen, M. Sagimon, E.
Kroon, J.E. van Aanhold 419
F.M. Mazzolani, T. Höglund and A. Mandara
SURFACE
Analysis of hot Formability of Al-4.6Mg-0.6Mn Alloy (AA5083)
431
Gang Fang, Pei-Gen Liao, Jie Zhou and Jurek Duszczyk Mechanical
Characterization of Aluminium Assemblies brazed with Gallium
441
E. Ferchauda, F. Christiena, P. Paillarda, H. Mourtona, P. Azaïsb,
C. Rossignol 451
Yuanding Huang, Xiuhua Zheng, Karl Ulrich Kainer, Norbert
Hort
XIIXII
TRANSPORT & AUTOMOTIVE
Tanja Kinzler and Harmen Schuitema Behaviour and Modelling of
Aluminium self-piercing Riveted Connections 471
N-H. Hoang, M. Langseth, R. Porcaro, A-G. Hanssen
for Transportation Purposes 479
W. Van Haver, B. de Meester, A. Geurten, J. Verwimp and J. Defrancq
The Effect of Sc Additions on Al-Mg Alloys for Aerospace
Applications 491
A. Kamp, S. Spangel, A.F. Norman
Transport & Automotive 2 499
Session leader: Bernard Gilmont
Sören Kahl Recent Developments in Aluminium Sheets for Automotive
Applications 507
Henk-Jan Brinkman, Olaf Engle, Jürgen Hirsch and Dietmar Schröder
Effects of Alloying Si and Cu to Al Alloys on Interfacial Reaction
and
Joint Strength in Dissimilar Metals Joints of Al Alloys to Steel
513
Akio Hirose, Hidetaka Umeshita, Yuichi Saito and Tomo Ogura The Use
of light Metals in the Design of the new Jaguar XJ
& other JLR Light Weight Vehicles 523
Mark White
Plenary Sessions
OPENING SESSION
CLOSING SESSION
& Prof. Frans Soetens
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311th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Michael Stacey
Professor of Architecture at the University of Nottingham and
director of Michael Stacey Architects.
Contact:
[email protected]
Abstract - This paper demonstrates the potential for aluminium to
contribute to the creation
of high quality contemporary architecture, throughout the globe.
Architecture that is durable
and beautiful, providing comfort and human well-being. It examines
how the architectural
other industries. The paper also explores the responsible sourcing
of construction products
and divergent views on recycled content. The case study
architecture will be drawn from the
author’s own practice and key international exemplars, identifying
the potential for aluminium
to contribute to human ecology.
Key Words: Aluminium, Architecture, Beauty, Durability, Ecology,
Excellence, Recyclability,
Responsible Sourcing and Sustainability
The power of aluminium resides in its usefulness to humankind. I
was inspired to study
New York, designed by Minoru Yamasaki. Aluminium has formed a
fundamental component of
the majority of my realised and award winning architectural
projects including; East Croydon
as the Aspect 2 Integrated Cladding System. Each project was
designed and developed in close
collaboration with experts from aluminium industries.
Throughout the globe aluminium has a vital role in the creation of
high quality contemporary
architecture, which is durable and beautiful, providing comfort and
human well-being. It is
pertinent to note that in Bagsværd Church by Jørn Utzon, a jewel
box of a building its exterior is
reminiscent of simple industrial or agrarian building this cloaks
an interior that is a celebration of
materials and modulated light that is conducted via thin cloudlike
concrete shells, adsorbing all
of the variations in the passage of the sun and weather. All
elements and components are bespoke
and designed by the architect, including the press braked aluminium
incandescent bulb holder
– however Utzon considered the aluminium framed Velux roof lights
to be a ‘standard product
[that is] impossible to improve’.
practitioners; including the careful study of precedents, the study
of materials, systems and post
doi:10.3233/978-1-60750-586-0-3
4 Michael Stacey / Aluminium, Architecture and Human Ecology2
car design. However the case for technology transfer can be
overstated – if you have a good idea
aluminium extrusion, be it a bespoke application or part of a
system, in my experience the earlier
was on my desk in three weeks – before rapid prototyping aluminium
extrusions were and are a
means of turning ideas into components – a physical realisation of
the drawing.
Technology Transfer
In automotive design there is a direct link between making a car
lighter and reduction in CO2
emissions, whilst maintaining strength and thus achieving NCAP
tested safety standards. This
explains the increased use of aluminium in automotive design.
Inventive detailing has reduced
the overall weight of the car. Alloy wheels, are not ‘green bling’,
they look beautiful and save
weight, running costs and CO2 emissions. Audi pioneered the use of
an aluminium space frame
car chassis in its A8. This inventive aluminium space frame chassis
with its curvilinear geometry
and complex junctions, is formed of extruded sections jointed with
vacuum cast aluminium
long aluminium die casting as its rear chassis legs, these are
believed to be the longest aluminium
die-castings in the world. Clearly this is a scale of aluminium
die-casting that is appropriate for
use in contemporary architecture.
doubly curved panels responding to the extensive interest in a
curvilinear architecture that has
been stimulated by digital design and digital fabrication. As an
architecture student in Liverpool
modern projects,s by architects including Zaha Hadid depend, on
this technological otherness.
I consciously studied new technologies including metal
fabrications, inspired in part by the
and you required a production run of thousands of parts, if not
millions, of identical components
to amortise the cost. The twentieth century paradigm was
standardisation and mass production,
and iconic standardisation. I never expected this technology to be
used directly in architecture
the superplastic aluminium cladding of the Sainsbury Centre at the
University of East Anglia
moulds were produced from CNC cut Styrofoam and cast in the Czech
Republic. The stainless
5Michael Stacey / Aluminium, Architecture and Human Ecology 3
steel was pressed by a subcontractor of Volvo in Sweden at 1815 ° C
and subjected to 1500
metric tonnes of pressure. This was prodigiously expensive cladding
that is said to have been
a project too far for Gartners of Germany who were subsequently
taken over by Italian Curtain
Walling specialists Permasteelsa.
Formtexx has seized an opportunity to create an affordable process
for the production
of doubly curved aluminium cladding. Inspired by car components,
including the aluminium
bonnets of Jaguar XF, Linda Barron and John Gould have formed
Formtexx as a jointed venture
with Whiston Industries, a UK based tool makers who produce body
work tooling for Jaguar,
Aston Martin and Bentley, and software specialists Stargate
resources. Formtexx can currently
produce double curvature aluminium cladding from sheets 1m2 using a
robotic manufacturing
‘M-Form’ process. Their aim is to manufacture doubly curved
aluminium panels up to 2 by
4 meters. A pioneering example of doubly curved aluminium used in
architecture is the semi
monocoque structure of Lord’s Media Centre, designed by Future
Systems and fabricated by
Pendennis Shipyard in 1999. Formtexx is not exclusively an example
of a company founded on
technology transfer, as Barron and Gould CNC textured the granite
of the Lady Diana Memorial
Fountain in Hyde Park, which was designed by Kathryn Gustafson and
Neil Porter.
The Future Builds on Aluminium
During 2009 the International Aluminium Institute [IAI] launched
The Future Builds on Aluminium sustainable material, see
http://greenbuilding.world-aluminium.org/.
required to evidence the responsible sourcing of aluminium:
Production Processes, Closing
Formtexx doubly curved aluminium cladding – displayed at the
Building Centre, London, 2009
6 Michael Stacey / Aluminium, Architecture and Human Ecology4
the Loop, Global Improvement, Urban Mining, End-of-Life Recycling,
Measuring Recycling,
Responsible Mining, Environmental Declaration and Life Cycle
Data.
The case studies demonstrate architectural excellence and the
potential contribution of
aluminium to human ecology are set out in a separate INALCO 2010
conference paper by the
author, The Future Builds on Aluminium: Architecture Case Studies.
Key case studies reveal that
by the careful selection of materials, and working with industry,
architects can produce affordable
of daylight whilst preventing solar gain. Architecture that
exploits the strength and lightness
of aluminium either in use and or in the prefabrication of large
elements in factory conditions,
and safer working conditions that off site fabrication offers. The
website also demonstrates
whereas their Cellophane House illustrates the recyclability of
aluminium, with almost 99% of
the embodied energy of the materials of the house having been
recovered when it was recycled.
Age of Resourcefulness
The excesses of the consumer society that started in the explosive
growth of North America
after the Second World War is coming to an end. Bill Bryson
observed that ‘by 1955 the typical
American teenage had as much disposable income as the average
family of four had enjoyed
more characterised by a paradigm clash between market
preconceptions and more responsible
modes of procurement combined with intelligent practices.
In its primary form aluminium is a high-energy product, it has a
high embodied energy.
little of a high energy material wisely and purposefully is a more
sustainable strategy than the
the responsible sourcing, effectiveness, durability, and the
potential recycling of any material.
BioRegional in its report on the Bedzed housing development [Fig
20], designed by Bill Duster
Architects, note that
‘The embodied energy of a material needs to be considered over the
lifespan of the
material, for example aluminium is a highly durable material with a
long lifespan of
[over] 60 years and therefore is an appropriate solution … despite
its high embodied
energy.’
Progress on Responsible Sourcing of Aluminium
made by its members, who represent 80% of the aluminium production
industry. It observes
7Michael Stacey / Aluminium, Architecture and Human Ecology 5
that an equal area of land is being rehabilitated as is being used
for Bauxite mining making
aluminium mining a land neutral industry. The Bauxite Mining Report
was produced biannually,
however from 2010 IAI will be producing an annual report.
The aluminium industry also strives to reduce its environmental
impact year on year. By the
end of the 20th century the energy required to produce a tonne of
aluminium had been reduced
by approximately 70% and further improvements continue to be
achieved. In 2010 only 14.5
kilowatt hours of electricity should be required to produce one
tonne of primary aluminium.
Globally over 50% of aluminium is smelted using hydro-electricity
and other renewable energy
technologies are being adopted by some extruders. It is key that
the aluminium industry provides
total transparency of data. It is an industry that has over the
past 40 years, in Feenberg’s terms,
achieved a democratic rationalisation.
Recycled Aluminium
Recycled aluminium requires only 5% of the energy to produce when
compared to winning
aluminium from Bauxite. This is like a car that averages 35miles to
the gallon being able to travel
is the type of step change that is needed as we face the risk of
global warming. Aluminium can
be recycled over and over again without loss of performance and it
can be up-cycled if necessary.
Aluminium is not like a fossil fuel – once used it is consumed –
about 75% of the aluminium
produced since 1888 is still in use. This represents the
sequestration of 47,800 petajoules of
energy this is the equivalent of the energy production for the
worlds 5 leading produces of
hydroelectricity for 8 years. There is evidence that we are
becoming a post-consumer society
where the everyday recycling of packaging enhances the cultural
perception of aluminium as a
sustainable material. The recycling rate of aluminium packaging in
Britain is only about 30%
whereas the Delft Report, shows recycling rates from buildings of
92 to 98%. However care
needs to be taken that architecture is not drawn into a discussion
based on packaging. A key role
of aluminium in architecture is its durability. Inventive reuse is
the best use of high quality built
architecture, rather than demolition and recycling.
There appears to be a gap between the aluminium industry and its
end users, particularly
architects when it comes to specifying recycled content. This gap
also exists between aluminium
companies trumpeted the recycled content for their products. For
example Isover, part of the
Saint Gobain Group, state that their glass wool insulation is
manufactured from 80% recycled
only recycled aluminium. Many environmental assessment tools, such
as LEED in the USA
allocate points for the use of post-industry or post-consumer
recycled content. All stakeholders
appear to agree on the recyclability of aluminium and that a
cradle-to-cradle approach should be
taken when considering the environmental impact of this metal.
Globally the available recycled
aluminium in 2008 was 18 million tonnes or 32% of global
production. Thus some in the
aluminium industry suggest that using a greater recycled content is
an unreasonable distortion
of this global resource. However in response to LEED North American
extruders will supply
billets with recycled content. For example Alumicor of Canada
supplies ‘architecturally extruded
aluminium that has a minimum pre-consumer (post industrial)
recycled content of 40% and
for extruded aluminium materials’.
8 Michael Stacey / Aluminium, Architecture and Human Ecology6
Viewed on a local basis the highest possible recycled content
appears to be more appropriate,
especially if the scrap aluminium and production can be sourced
locally thus minimising material
and component miles. An exemplar of this approach is the cast
aluminium louvers of Heelis:
National Trust Headquarters at Swindon designed by Feilden Clegg
Bradley Studio. Peter Clegg
performance of typical commercial buildings built to similar
budgets. The 2-storey deep plan
building has been designed to provide an excellent working
environment and to minimise energy
usage, with the opportunity of approaching zero CO2 production in
operation. Aluminium was
one enters – the reception desk is also fabricated from recycled
cast aluminium.
along each ridge are shaded by projecting photovoltaic panels and
ventilation “snouts” emerge
to provide summertime natural ventilation. The roof integrates
Photovoltaic panels that shade the
north lights. The natural light from the roof penetrates through a
series of double height spaces
2 emissions from the building
2/m 2
then the highest standard within this scheme. Another example of
local recycling is provided by
closed loop pre-consumer recycled off cuts.
BRE Environmental Assessment Method [BREEAM] was developed by
Building Research
new standard of sustainability for exemplary developments. To
achieve and retain an Outstanding
rating the building owners and designers must agree to three years
of post occupancy evaluation.
A true measure of performative architecture, if this is not
undertaken or the performance is
unsatisfactory the BREEAM award is reduced to Excellent. The other
major change to BREEAM
is the reward of innovation, here the aluminium industry may well
be able to collaborate with
designed by Amanda Levete Architects. This is a beautiful project,
which brings new life and
a much higher standard of performance and comfort to a building off
Oxford Street in London.
.
9Michael Stacey / Aluminium, Architecture and Human Ecology 7
8902 the British Standard on Responsible Sourcing of Construction
Products. This effectively
supersedes Building Research Establishment’s [BRE’s] ‘framework
standard responsible
sourcing of construction products’ BES 6001 published in 2008. I am
concerned that BRE,
once the Building Research Station and part of the British
Government, now that it is a private
company acts as a hub monopoly. Thus the material criteria in both
BREEAM and Code for
also nest other products into these environmental assessment tools
such as SAP calculations and
related software.
Britain, possibly in the context of the European Union, requires a
rigorous alternative
accreditation body for the environmental credentials of building
products and materials based on
Taking the example of a domestic window the functional unit is 1m2,
whether the window is
made from PVC, Timber or Aluminium. Thus the strength of aluminium
is negated, nor do I
It is now possible to specify and receive a 40-year guarantee on
polyester powder coating on
material from cradle to cradle. Therefore it is ethically wrong if
this is distorted for commercial
gain. The Council for Aluminium in Building [CAB] is working with
all material sectors on
window manufacturing sector.
However progress is being made, an aluminium window has achieved an
A rating in the
double-glazed’, and it achieves A+ in eight out of 14 assessment
criteria. Again the functional
unit is 1m2 of a double glazed window or clear glazed curtain
walling. This makes even less sense
large double glazed units that minimise edge effects, are also
attractive and popular. Furthermore
a low emissivity coating within the double glass unit is now the
norm. On many projects the
best option is to evaluate the windows or curtain walling using a
bespoke assessment within
BREEAM or CSH and thus achieve a fair rating for the
products.
Olympic Delivery Authority has placed a great emphasis on the
responsible sourcing of all
the saddle shaped roof of the 2012 Olympic Aquatic Centre designed
by Zaha Hadid Architects
is being clad with aluminium. The Aquatic Centre is intended to
form an inspirational gateway
to the London games. An aluminium standing seam roof was selected,
as it is cost effective,
could accommodate the gentle double curvature of the roof and is
fully recyclable – should this
minimise the use of non-standard sheets.
10 Michael Stacey / Aluminium, Architecture and Human
Ecology8
Nottingham House - Zero Carbon and Prefabricated
The Nottingham House, designed by Rachel Lee, Ben Hopkins and Chris
Dalton in the author’s
of the process of assembly and disassembly for Madrid. The house
was fabricated in eight
in Eindhoven the house will have been through the ten tests of the
Solar Decathlon competition
that range from cooking for ones neighbours using only solar power
to the architectural merit of
the project.
The house has been built by architecture students at the University
of Nottingham and the
led by the University of Nottingham. Contractually it is more like
partnering than conventional
successful built using partnering. This encourages close
collaboration with the supply chain and
specialists within industry. The Nottingham House team is unlike a
focused main contractor and
2
triple glazed windows. It will return to Nottingham to become a
permanent home that achieves
been designed as a family home with an inviting spatial quality and
inventive details. It has been
designed as a response to the poor quality production of current
mass house builders. It achieves
depending on the climatic situation, local traditions and
culture.
Aluminium plays a vital role in the construction of the Nottingham
House. Stock aluminium
angles have been used to create contemporary interpretations of
skirting boards and architraves.
Stock aluminium angles channels support structural glass
balustrades. The corners of the
thermowood timber cladding are supported by brackets made of three
stock aluminium angles,
detail is to minimise the material in the insulation zone bridging
between the structure and the
cladding. 2ºK
combination of timber with insulated inserts, pultruded thermal
breaks and polyester powder
from the fact that these window sections are bulky they potentially
represent the material future
of architecture, with each material playing a distinct role, the
timber safely in the warm dry
interior capturing CO2, the insulation ensuring that the low
U-value is achieved, the pultrusion
stops thermal loss through the frame and the aluminium retains the
triple glazing and provides
The house is completed by aluminium rainwater hoppers and
downpipes, supplied by
11Michael Stacey / Aluminium, Architecture and Human Ecology
9
Crown Aluminium and polyester powder coated by Birmingham Powder
Coaters. This pair of
companies demonstrated the aluminium industries ability to practice
just-in-time manufacturing.
The Nottingham House research team is working on the market
viability of the constructional
system that has been designed to create homes in climatic
conditions throughout Europe. The UK
government’s Housing Minister John Healey MP on visiting the
Nottingham House at Ecobuild
observed, “ I think it is priceless. It is a demonstration of new
ideas and how they can be put into
practice … in the long term we need to build to this standard,
across the board”.
Conclusion
resourcefulness where materials were used with care and skill to
form architecture and the built
material may already be over 120 years old, it will remain useable
throughout the century and
2 produced
built environment has the potential to close this gap, making the
aluminium industry net carbon
architects and industry whilst recognising the key role of
inhabitation has the potential to be in
performs well, is durable and beautiful, an architecture that is
well understood by humankind
and thus is appropriated. The case studies of this paper
demonstrate the potential for technique,
culture and inventiveness to be able to sustain human
ecology.
References
[1]
[2]
by impact of humankind on the atmosphere of the Earth.
[6]
Developments – Part 1, Nicole Lazarus, Bioregional and DT1,
2002
[8] The pace of industrialisation in China is modifying the global
data on aluminium production with areas of
[9]
[10]
[11]
[12]
[20] www.bre.co.uk/greenguide
[21] The ten tasks of the Solar Decathlon competition are:
Architecture, Engineering, Market Viability,
Solar Decathlon.
[22]
d
1311th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Technologies – for the Aluminium Industries
W.M. Thomas, J. Martin and C.S. Wiesner
TWI Ltd, Great Abington, Cambridge, CB21 6AL, UK.
[email protected]
[email protected]
[email protected]
Abstract - The basic principles and the continuing development of
friction technologies
are described with particular emphasis on friction stir welding
(FSW) variants from the
perspective of discovery, invention and innovation. This paper
further outlines the feasibility
work that has been carried out to develop self-reacting (bobbin)
stir welding for welding
25mm thick aluminium alloy material.
Introduction
The characteristics of the FSW technique [1, 2] can be compared
with other friction process
inertia, linear, orbital and arcuate friction welding variants are
used to join two bars of the same
occurs equally from each bar to form a common plasticised
‘third-body’. However, differences
in diameter or section, lead to preferential consumption of the
smaller component. Differences
of material strength in one of the parts to be joined also lead to
preferential consumption of
the comparatively softer material [3]. The unequal consumption and
temperature distribution
in rotary friction welding between different diameter bars has
already been studied [4, 5]. This
preferential consumption and reprocessing of one component in a
friction system has been put
to good use in the development of friction surfacing, friction
hydro pillar processing and friction
pillaring, radial friction welding and friction plunge welding.
Friction stir welding is a further
development in that only a small workpiece weld region is
processed, without any macroscopic
geometry changes to form a solid-phase welded joint.
the consumed and reprocessed material is introduced into the
friction system. This introduced
material, which has a comparatively lower thermal softening
temperature than the components
or be used as a joining medium.
doi:10.3233/978-1-60750-586-0-13
14 W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies2
temperature distribution between a comparatively small diameter
rotating consumable bar
techniques, therefore, rely on producing suitable temperature and
shear conditions within the
substrate, and between the tool and the workpiece in FSW.
In friction surfacing any increase in temperature differential (by
the intrusion of cold substrate
material) enhances the deposition mechanism and allows
comparatively harder materials to be
deposited onto nominally softer materials [8]. The inherent
temperature gradient leads to minimal
dilution. However, in FSW the intrusion of cold workpiece material
and the anvil support plate
can, in some cases, hinder the welding performance.
Bobbin stir welding
support plate. The constraint and support necessary of the bobbin
weld region is provided by
near and far side shoulders of the tool [1]. Friction stir welding
using a self-reacting bobbin tool
gap ‘bobbin tool’ [9, 10] and one as the adjustable [1] or
‘adaptive technique’ (AdAPT) [11-13].
between the shoulders during the welding operation.
The self-reacting principle of the bobbin technique means that the
normal down force
required by conventional FSW is reduced or eliminated. The reactive
forces within the weld are
contained between the bobbin shoulders (Figure 3).
Figure 1. Friction process variants.
15W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies 3
Figure 2. Self-reacting bobbin stir welding, showing near and far
side shoulders.
Figure 3. Bobbin tool showing self-contained reactive forces
Figure 4.
gap bobbin tool.
16 W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies4
Trials in 25mm thick 6082-T6 aluminium using the above arrangement
produced good
quality welds. Figure 4 shows a metallurgical section of the widths
of the larger diameter (drive
side) shoulder and the smaller opposed shoulder in the weld area.
Unlike single-sided stir welds,
features within the thermo-mechanically affected zone (TMAZ) can be
seen in Figure 4.
The hardness distribution across the transverse direction in the
25mm thick 6082-T6
aluminium weld is shown in Figure 5. The minimum hardness is
located in the HAZ near the
interface between the TMAZ and the HAZ.
Figure 5. Hardness survey mid-thickness in 25mm thick 6082-T6
aluminium weld
of the notch tip between the lapped plates was evident.
Figure 6.
a) Three point bend test on 25 mm thick plate
b) Hammer bend test, failed in parent material, carried out on 12
mm thick lapped plates
17W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies 5
Bobbin type tools are similar to other standard FSW tools that are
driven from one side
in that the tool behaves as a rotating cantilever. The use of a
tapered probe for a simple (non-
less material during welding than a cylindrical pin-type probe. The
use of a tapered probe for the
bobbin tool enables a proportional reduction in the diameter of the
lower shoulder of the bobbin
tool. A reduction in the lower shoulder diameter results in lower
frictional contact and resistance,
therefore less torque and bending moment on the tool. The
additional frictional contact provided
by the lower shoulder and the absence of a backing anvil, which
acts as a heat sink, means that
the operating temperature will be higher than that of a similar
conventional weld. Moreover,
owing to the limited thermal conduction path from the shoulder
furthest away from the drive
side, this shoulder will run slightly hotter. In some situations
thermal management techniques
such as cooling the shoulder by an air blast are used. Tool design
and process conditions will
additional heat generation.
Preliminary trials have also shown that lap welds produced by the
bobbin technique have fewer
problems with the adverse orientation of the notch at the edge of
the weld.
Certain bobbin welds can reveal a mid-thickness ‘blip’ that appears
on the advancing side.
Non-optimised welds can also be characterised by imperfections that
appear in the mid-thickness
near the ‘blip region’ of the weld on the advancing side, see
Figure 7. These imperfections are
conventional FSW technique is used.
Figure 7. Non-optimised bobbin welds in 25mm thick 6082-T6
aluminium alloy showing a mid-thickness ‘blip’ and
imperfections on the advancing side.
18 W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies6
reactive forces on the upper and lower tool shoulders. The bobbin
tool operates within a sleeve
which provides vertical guidance and the rotational drive via a
keyway [1].
The instrumentation chart shown in Figure 9 provides clear evidence
of the very low axial
(z) force, well balanced around the zero-force datum line. The
torque remains relatively stable
during the main equilibrium stage. The slight reduction in torque
from the beginning to the end
Figure 8.
Figure 9.
19W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies 7
to become smoother as process parameters are further optimised.
Further investigation into this
phenomenon is ongoing. Nevertheless, the investigation so far is
very encouraging.
Trials in 25mm thick 6082-T6 aluminium using the above arrangement
produced good-
quality welds see Figure 10. Although the macro-structural features
are nominally more balanced
The use of both the aforementioned bobbin techniques typically
causes less distortion than
conventional FSW due to a more balanced heat input. Moreover, the
low welding forces in the Z
Double driven bobbin techniques
For certain applications, bobbin tools that are driven from both
ends can be envisaged (Figure
11).
behaves as a rotating cantilever. A bobbin tool that is driven from
both ends and designed for
uniform stress, means that the aspect ratio of the probe can be
altered (decrease in cross-section
bending forces can be shared between both ends, the cross-section
of the probe must be able to
accommodate the reactive forces that tend to push the shoulders
apart.
Double-driven and double-adaptive bobbin techniques
The concept of a double-driven bobbin also includes the use of a
double-adaptive technique
whereby both shoulders can be adjusted and a load applied from both
ends, see Figure 11b. The
latter arrangement will reduce the reactive forces transmitted
through the probe and enable FSW
Figure 10.
20 W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies8
to tackle thicker plate material than currently possible. This
concept is expected to increase the
and may even provide welding speeds faster than conventional FSW
for thick plate welding.
complex shapes.
Discussion and concluding remarks
For conventional FSW, a stop and restart can if necessary be
accommodated anywhere along
achieved the tool needs either:
a) To complete an open-ended joint;
b) To break out of the work piece;
c) To reverse back the same way that it entered (a double welding
operation).
There are, however, a number of features that make bobbin stir
welding attractive. Two
lost through the anvil support plate. The containment of reactive
forces within the tool itself
means that compressive deformation (squashing) of the probe does
not occur. The probe part
comparatively higher levels of torsion and bending with tensile
rather than compression forces
being applied through the probe.
penetration, lack of penetration or root defects. The developments
in bobbin tool welding of
enclosed seams such as extrusions will with certain applications
eliminate the need for internal
Figure 11.
a) Driven from both ends
b) Driven from both ends and reactive force applied from both
ends
21W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies 9
backing bars to support the weld region. Preliminary trials have
shown that lap welds produced
by the bobbin technique have fewer problems with the adverse
orientation of the notch at the
leading edge of the weld.
Many of the discoveries, inventions and innovations of FSW
technology [1, 2] stems from
a sequence of events as shown in Figure 12. While this approach is
not meant to be prescriptive
for every investigator or every situation it may provide insight
for some investigators in some
situations. The long term competitive position of most industrial
organisations depends on their
determination to remove barriers to technical evolution within the
species of their technology
base. Discovery, invention and innovation are more easily desired
than accomplished and it is the
creative insight that moves from a state of not knowing to
discovery and a new understanding.
It is true that discovery, invention and innovation precede product
development, but the actual
mechanism that enables creative insight is not fully understood
[14, 15].
Figure 12. Technical evolution - discovery, invention and
innovation
Acknowledgements are made for the support and contributions provide
I M Norris, M J Russell,
I J Smith, L Barrett, D D R Lord, D G Staines and C Stanhope.
References
[1] W.M. Thomas, E.D. Nicholas, J.C. Needham, M.G. Murch, P.
Temple-Smith and C.J. Dawes. ‘Improvements
[2] W.M. Thomas, I.M. Norris, D.G. Staines, and E.R. Watts.
‘Friction Stir Welding – Process Developments and
Variant Techniques’, The SME Summit 2005, Oconomowoc, Milwaukee,
USA, August 3-4th 2005.
[3] D.J. McMullan and A.S. Bahrani. ‘The mechanics of friction
welding dissimilar metals’. Second International
22 W.M. Thomas et al. / Discovery Invention and Innovation of
Friction Technologies10
Symposium of the Japan Welding Society on Advanced welding
technology, 25-27 August, 1975, Osaka,
Japan.
[4] A. Hasui A et al. ‘Effect of the relative difference of bar
diameter on the friction welding of different diameter
bars’,. IIW Doc. III-679-81, 1981.
[5] K. Fukakusa and T. Satoh. ‘Travelling phenomena of rotational
plane during friction welding. Application of
Friction Hardfacing’, International Symposium on Resistance Welding
and Related Welding Processes, 10th-
12th July 1986, Osaka.
[6] E.D. Nicholas and W.M. Thomas. ‘Metal deposition by friction
welding’. Welding Journal, August 1986, pp17-
27.
[7] G.M. Bedford. ‘Friction surfacing for wear applications’.
Metals and Material, November 1990, pp 702-705.
[8] W.M. Thomas. ‘Solid phase cladding by friction surfacing’.
Welding for the Process Industries, International
Symposium, April 1988.
[9] K.J. Colligan, and J.R. Pickens. ‘Friction Stir Welding of
Aluminium Using a Tapered Shoulder Tool’, Friction
Stir Welding and Processing III, eds K V Jata, Mahoney, R S Mishra,
and T J Lienert, TMS Annual Meeting, San
Francisco, 2005, pp 161-170.
[10] L.D. Graham. ‘Low Cost Portable Fixed-Gap Bobbin Tools FSW
Machine’, poster presentation at the 86th
Annual AWS Convention/2005 Welding Show.
[11] W.M. Thomas and G. Sylva. ‘Developments of Friction Stir
Welding’, ASM Materials Solutions 2003, Conference
& Exposition, 13-15 October 2003 Pittsburgh, Pennsylvania,
USA.
[12] F. Marie, D. Allehaux, and B. Esmiller. ‘Development of the
Bobbin Tool Technique on various aluminium
alloys’ Fifth International Symposium on Friction Stir Welding,
Metz, France, 14-16 September 2004.
[13] G. Sylva, and R. Edwards. ‘A Feasibility study for self
Reacting Pine Tool Welding of Thin Section Aluminium’,
Fifth International Symposium on Friction Stir Welding , Metz,
France, 14-16 September 2004.
[14] W.I.B. Beveridge in: ’Seeds of Discovery’, Heinemann
Educational Books, London, 1980, pp 83. (ISBN 0435
54064 5).
2311th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Light Metals to survive in a Sustainable World?
Mark White
Chief Technical Specialist – Body Engineering Jaguar & Land
Rover Product Development
The car industry is under increasing pressure to reduce emissions.
In Europe there is now an
agreed industry roadmap to reduce emissions by 3% per year over the
next 20 years, with the
doi:10.3233/978-1-60750-586-0-23
24 Mark White / Why does the European Car Industry need Light
Metals to survive in a Sustainable World?2
st
problem is likely to get worse rather than better in the short term
without concerted global action.
urgency.
25Mark White / Why does the European Car Industry need Light Metals
to survive in a Sustainable World? 3
based power generation. The European car manufacturers have already
risen to this challenge
prior to any legislation, agreeing through industry bodies such as
ACEA & the NIAGT to reduce st Century to a target of
be able to continue with the levels of personal transportation we
have today.
construction was a unibody or monocoque steel spot welded body for
volume manufacture.
This Manufacturing method, although investment intensive for the
stamping dies & the body
construction facility, enabled low piece cost, ease of repair &
satisfactory performance for every th
vehicles in any volume. The search for light weight vehicle
solutions really gained momentum
when the combination of better fuel economy (to combat increasing
fuel costs in Eu especially)
growing demand from consumers for bigger more comfortable cars
meant that cars were
or better performance in structural load cases with the opportunity
to down gauge to save weight,
best the weight of the body stood still & in most cases it
continued to get heavier into the
26 Mark White / Why does the European Car Industry need Light
Metals to survive in a Sustainable World?4
21st Century. The proliferation of these new steels also brought
their own issues of formability,
joining & corrosion protection & in some instances there
were also potential in service issues as
the yield strength was increased to higher & higher limits.
Ultimately Body Engineers concluded
that whilst for strength dominated parts advanced high strength
steels (AHSS) & ultra high
strength steels (UHSS) had their applications for box sections
& reinforcements, where there
were mainly stiffness dominated parts, they had little or no weight
saving opportunity. At this
point, at least 2 of the major aluminium primary producers (Alcan
& Alcoa) were actively selling
the use of aluminium sheet as an alternative to steel for weight
saving, especially for Closures
(Hang on parts), where most of the load cases were for stiffness
not strength (customer abuse,
dings & dents performance, etc) & where by increasing the
steel part gauge by 50% there would
still be the opportunity for a 50% weight save in aluminium versus
the steel equivalent for
broadly similar performance. However there were still a number of
technical & manufacturing
issues to overcome with the alloys that were available at the time
& this is when the real AIV
(Aluminium Intensive Vehicle) studies began between the OEM's &
the aluminium Industry.
It should be noted that whilst price difference between steel &
aluminium was an issue to the
respect to volatility & was closing the gap to steel in real
terms, although to date this has not be
consistent especially in recent years.
There have been several approaches to aluminium intensive vehicles,
with many low volume
sports cars adopting a space frame approach using a combination of
casting, extrusions & sheet
parts. With joining technology ranging from MIG/MAG, spot welding,
riveting & adhesive
bonding, however very little of this technology is transferable to
higher volume BIW builds.
from relatively low volumes of the XJ & XK models to volumes of
over 100,000 units a year
to meet the ongoing Industry challenges that will impact on all our
vehicle range over the next
27Mark White / Why does the European Car Industry need Light Metals
to survive in a Sustainable World? 5
20 years. This led us to adopt what is essentially a unibody (or
Monocoque) construction, using
largely pressed parts, but also using what we refer to as open part
thin wall castings & extrusions
where there is a cost, complexity or attribute driver. JLR has
worked with Novelis to develop
alloys, pre-treatments & lubricants, when combined enable us to
make very complex aluminium
comparable performance. High Pressure Die Castings (HPDC) are added
to the sheet structure
where there are applications that require continuous sections often
in package constrained areas
where a higher strength T6 alloy can be used (e.g. XJ A
Pillar/Cantrail). The joining technology
adopted as part of the JLR LWV technology is a combination of Self
Pierce Rivets (SPR's) &
adhesive bonding, similar to that used in Aerospace applications.
The advantages of using what
are essentially cold joining process's are that there is no
disruption in the mechanical properties
of materials being joined, it is easy to join dissimilar materials,
there is no distortion of the
build facility that has no welding, further enhancing the overall
carbon footprint of our LWV
models.
A major part of the JLR LWV Manufacturing strategy is the use of
secondary metal & the closed
loop recycling concept which was put in place with the bespoke
Press Shop facility at Castle
Bromwich, which is now being applied to all JLR Press Shops &
across all of our external
stamping suppliers to maximise the reuse of all offal generated
through the production process.
Novelis also collect all of the offal generated through their blank
production process & when
combined with JLR scrap, this is then re-melted to mean that up to
50% of the metal used at JLR
is from secondary metal, reducing our overall CO2 footprint
further. JLR & Novelis with other
related partners are working with the UK Government to investigate
increasing this to up to 75%
metal. The use of recycled material going forward is a key part in
the LWV Life Cycle Analysis
(LCA) if aluminium is to be the material of choice of the Car
Industry & more efforts need to be
made Industry wide & with the consumer to eliminate bad
practice & worst still, the amount of
28 Mark White / Why does the European Car Industry need Light
Metals to survive in a Sustainable World?6
2911th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Aluminum Structures
Bucknell University, Lewisburg, PA, USA,
[email protected] The
TGB Partnership, Hillsborough, NC, USA, randy.kissell@
tgbpartnership.com
Abstract - With the advent of the 2010 Aluminum Association’s
Structures, structural engineers will be required to design using
new stability provisions.
Second-order effects, including P- and P- moments, will need to be
directly accounted for
in the analysis. Factors known to accentuate these effects, such as
geometric imperfections
and member inelasticity, will also need to be considered. This
paper provides an overview of
these provisions and describes a study that investigated their
effectiveness.
1. Introduction
In the US, the Aluminum Association’s (AA) [1], widely
columns.
have not directly considered the stability of structural systems as
a whole. For example, the
of loads acting on the displaced location of joints in a structure.
Therefore, the strength of a
the strength of its weakest member, and some collapses have been
attributed to this.
In 2005, the AA decided to address the issue of the stability of
structural systems in the 2010 edition
doi:10.3233/978-1-60750-586-0-29
30 Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures2
those that appear in the 2010 American Institute of Steel
Construction’s (AISC)
Structural Steel Buildings [2]. Because of differences in (1) the
stiffness and strength of steel
and aluminum, in particular that the E/ y ratio for steel is
approximately twice that of aluminum,
study is presented below.
This chapter addresses the analysis requirements (calculation of
required strengths) and design
requirements (calculation of available strengths) for the structure
as a whole and for each of its
components. The actual unbraced length of the member (i.e., an
effective length factor of k = 1)
analysis requirements are met.
1. All member and connection deformations are accounted for.
2. Second-order effects, including both P- and P- moments, are
included.
3. Geometric imperfections, such as frame out-of-plumbness and
member out-of-straightness,
4. Member stiffness is reduced to account for:
a. inelasticity or partial yielding of members
, where
in which Pr is the required axial compressive strength (i.e., axial
force in member) and Py is the
axial yield or squash load (i.e., Py = Ag y).
modulus of elasticity in the analysis model.
must be included in the analysis, including loads on structural
system elements that are not part
of the lateral load-resisting system.
(1)
31Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures 3
3. Basis for Study
formulating the equations of equilibrium on the deformed, and
perhaps partially yielded, geometry
of the structural system. Because the details in accounting for
member inelasticity ( -factor of
for steel buildings, their applicability to aluminum structures
deserves to be questioned.
Compressive axial stresses on the order of 30 to 50 percent of the
material yield strength can
result from the steel fabrication process and such stresses can
obviously accentuate the partial
buckling of a column). Based on an extensive calibration study [3],
the AISC determined that
the relatively simple parabolic expression provided by Eq. 1, which
was originally developed
stiffness of members subject to high axial compressive loads. For
frames with slender members,
where the limit state is governed by elastic stability (i.e., = 1.0
with P/Py factor can be employed because it is approximately equal
to the product of the AISC resistance
out-of-straightness.
In contrast, aluminum sections are typically extruded and then
pulled to straighten. This
stretching process typically removes residual stresses. Aluminum
sections can also be fabricated
Differences in the stress-strain relationships for each material
may also be a factor in determining
the appropriateness of adopting the AISC provisions. Hot-rolled
steels typically have a fairly
linear constitutive relationship with a pronounced yield point. On
the other hand, the stress-
stain relationships for most aluminum alloys are inherently
nonlinear and without pronounced
yield points. Hence, the above reasons (e.g., absence of residual
stresses) for not employing the
parabolic form of Eq. 1 may be offset by the need to model a
nonlinear material.
4. Computational Study
To investigate the above situation, the Aluminum Association
conducted a pilot study using
one of the frames appearing in the original AISC calibration
studies mentioned above. This
symmetrical portal frame is shown in Fig. 1. Two ratios of
beam-to-column stiffness were
used, one of which included assuming rigid beams with
(EI/L)c/(EI/L)b = 0 and the other with
EI/L)c/(EI/L)b = 3. Using a bi-symmetrical I-shape, both
major-
and minor-axis bending behavior of the columns was investigated. In
all cases, members were
assumed to be fully braced out-of-plane.
32 Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures4
Figure 1. Symmetrical portal frame used in computational
study.
to determine system strengths and obtain interaction curves for a
wide range of resulting
combinations of axial force and bending in the columns.
element program ADINA [5] was employed. Fully integrated, 4-node
shell elements (MITC4)
were used to create three-dimensional models of the I-sections. The
cross section was modeled
The number of elements along the length of the member was varied to
maintain an element
All models considered both geometric (large rotation/small strain)
and material (multi-linear
plasticity) nonlinear effects. A nonlinear stress-strain response
(Fig. 2) was explicitly incorporated.
Initial imperfections, including member out-of-straightness and
frame out-of-plumb, were
elastic, whereas column elements were permitted to yield.
Figure 2. Stress-strain relationship used in ADINA analyses.
33Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures 5
Each ADINA analysis was performed until a strength limit state was
detected. Such limit states
order effects.
MASTAN2 models second-order effects through the use of element
geometric stiffness matrices
during each load increment.
equation:
where, Pr and Mr are the axial force and bending moment from the
MASTAN2 analysis, Pc the
with kL = L, and Mc Mr = bS y with
b S is the elastic section modulus). Frame out-of-plumbness of
H/500 was included
in these analyses but member out-of-straightness was not. The
latter is included in the AA
Pc.
5. Results
requirements can be assessed by comparing P-M interaction plots of
the limiting strengths from
the AA-MASTAN2 approach to the “actual” strength determined from
sophisticated geometric
and material nonlinear ADINA analyses.
Figures 3 and 4 contain these results for major-axis and minor-axis
bending cases, respectively.
EI/L)c/(EI/L)b = 0, and one for a
EI/L)c/(EI/L)b = 3. In each plot, two sets of AA-
MASTAN2 and ADINA curves are provided.
plastic moment (WLc/Mp, with W and Lc Mp = Z y where Z is the
plastic
section modulus). The second set can be used to compare ratios of
the total moment (including
Mc/Mp). Each point on the
Q and lateral
load W (just under 50 separate ADINA and MASTAN2 analyses were
performed in this study).
Pr
Pc
+ Mr
Mc
1.0 (2)
34 Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures6
Based on Figures 3 and 4, several observations can be made:
ratio WLc/Mp to the total moment ratio Mc/Mp at various values of
P/Py indicates that second-
P/Py = 0.1, the second-
ger values of P/Py.
2. By comparing the AA-MASTAN2 and ADINA total moment ratios Mc/Mp
at various values of
P/Py, it is clear that the “actual” bending moment capacity of the
column in the presence of any
Figure 3. Interaction curves for major-axis bending of
column.
35Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures 7
limit capacity of bZ y.
(e.g., AISC) a bilinear curve is used, which permits larger
strengths at low- to intermediate
values of axial force, ranging from approximately P/Py = 0.1 to
P/Py = 0.5.
3. The WLc/Mp curves also provide a direct indication of the
ultimate strength of the frame
predicted by the AA-MASTAN2 and ADINA approaches. For example, the
coordinate
Figure 4. Interaction curves for minor-axis bending of
column.
36 Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures8
pair (WLc/Mp , P/Py) = (0.2, 0.4) represents failure at gravity and
lateral load combination
of Q = 0.4Py and W = 0.2Mp/Lc. In all major-axis bending cases, the
strength predicted by
the AA-MASTAN2 approach is less than the “actual” strength
predicted by ADINA. This
conservatism is repeated for all minor-axis bending conditions with
the exception of the high
axial load case (P/Py EI/L)c/(EI/L)b =
3. The over-predicted AA-MASTAN2 strength, however, is quite small
(see lower plot in Fig.
4). For a column-to-beam stiffness of (EI/L)c/(EI/L)b = 3, a design
method based on effective
length would use an effective length factor of approximately k =
2.5, where as the AA stability
provisions permit the use of k = 1.0.
4. The largest P/Py Substituting these values into Eq. 1 results in
relatively inconsequential
L/r = 20 with r I A ) were
investigated in this study, it should be noted that larger
slenderness L/r values more common
to design would result in smaller column strengths (i.e. lower P/Py
values) and hence, even
larger (closer to 1.0) and less consequential -factors.
6. Summary/Conclusions
This paper presents a pilot study that evaluates the new stability
provisions that appear in the
2010 Aluminum Association’s . A portal frame similar to
.
Based on this study, it appears that the AA stability provisions in
conjunction with their use
of a single linear interaction equation for designing beam-columns
provide moderate to fairly
conservative results.
The AA use of the stiffness reduction factors
not unreasonable although it is unclear if the -factor is
necessary.
It also shows several cases where the AA stability provisions are
adequate for allowing the
routine use of an effective length factor of k = 1, even in cases
where an effective length design
method requires using two to three times that value.
Additional studies are warranted to determine if the AA could avoid
the use of a -factor in
sections, where the effects of welding may result in substantial
residual stresses and thus justify
using the -factor.
7. Acknowledgement
The authors thank the Aluminum Association for their support of
this research under grant
37Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures 9
8. References
Chicago, IL, 2010.
[3] Surovek-Maleck, A., White, D.W. and Ziemian, R.D., Validation
of the Direct Analysis Method, Structural Engineering, Mechanics
and Materials Report No. 35, School of Civil
and Environmental Engineering, Georgia Institute of Technology,
Atlanta, GA, 2003.
[4] Bleich, F., Buckling Strength of Metal Structures, McGraw-Hill,
New York, 1952.
[5] ADINA, Theory Manual, ADINA Research and Development, Inc.,
Watertown, MA,
2009.
[6] MASTAN2, developed by R.D. Ziemian and W. McGuire, version 3.2,
www.mastan2.com,
2009.
[7] McGuire, W., Gallagher, R.H., and Ziemian, R.D., Matrix
Structural Analysis, Wiley,
Hoboken, NJ, 2000.
38 Ronald D. Ziemian et al. / Developing Stability Design Criteria
for Aluminum Structures10
3911th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Utilizing the opportunities of post consumer aluminium scrap.
Frans Bijlhouwer MBA
Quality Consultants V.O.F., the Netherlands.
Can there be an end to the continuously growing primary aluminium
industry and can the
recycling industry catch up or even replace it? It all depends on
the global demand for
aluminium products in let’s say 40 years from now and what will
happen with the almost
endless stream of aluminium products to the end of its life
cycle.
It seems that if there is a political wish to do it, an expanding
recycling industry can boost jobs,
reduce CO2 emission big time and balance it out with the primary
industry.
For the professional there is no need to explain the unique
characteristics of aluminium such as
the absence of quality loss by recycling and that it needs only 5 -
8% of the original energy to
produce aluminium to recycle aluminium back to its original
state.
This makes, as we all know, recycled aluminium the best alternative
for primary
aluminium.
These unique characteristics create an increasing demand for this
metal.
According to the IAI1, over the last few years, more than 25
million tons of aluminium
products are put to use on the global market as products every
year.
Since the industrialization of the aluminium producing process in
1886, more than 640
million tons of aluminium products have been put in use. Taking
into consideration that these
aluminium products in use have a certain life endurance, it should
be obvious that at a certain
moment in time this enormous mass of metal will be disposed of and
be ready for recycling.
There are two aspects that will determine that moment.
on the characteristics of the product or its economical life.
A point of uncertainty is that these products have a considered
longer life than ever has been
expected. For example, did we expect that aluminium in buildings
would stand for 30 years,
nowadays we know that its life easily can be stretched to 50 years
and most likely even longer,
underlining the durability of aluminium and its products.
From most aluminium products we still do not know exactly the life
endurance in economical
use. From cars we know that the bulk of the aluminium that has been
offered for recycling, has
1 IAI, International Aluminium Institute
doi:10.3233/978-1-60750-586-0-39
40 Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow?2
been in use for about 20 years, from cans we know that the recycled
metal is reused as a can as
short as within 60 days. Between these two examples is a wide
spectrum of products with its own
The second important aspect is the recycling rate indicating the
percentage of the product being
cans, cars and all other aluminium products. The EAA2 has
determined that some buildings
containing aluminium, have been demolished while all the aluminium
in them were offered for
recycling with high recycling rates of above 90%.
But this was just a spot check. Other buildings recently have been
demolished in Europe
while not all the metal was offered for recycling [1].
From cans we know that certain countries do an excellent job and
reach high recycling rates
smelters might produce 300,000 tons of aluminum per year, less than
half of what thirsty
Americans toss in the garbage can each year” underlining the effect
and underestimated scale of
the recycling of aluminium.
Well known is that can recycling in the US is about 65% and the EU
approaches the 70%
level, while in the UK the recycling rate for cans is only
52%.
The yearly published Mass Flow Model from IAI, gives a view on the
volume of aluminium
that is in use and also allows us a view on the actual
recycling.
Figure 1: IAI Mass Flow Model 2008
Some remarks should be made about this model, which suggests that
almost all metal will be
recycled. If we know from research that the average recycling rate
over all products is 72%, then
it is clear that from this 640 million tons, the remainder (thus
28%) is not recycled.
2 EAA, European Aluminium Association
41Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow? 3
(directly) to recycling, despite what we as the aluminium industry
promise to our users.
From our research we found also, that as a consequence of recycling
rates and life endurance
expectations, compared with the different alloys, wrought and cast,
and the different sectors the
metal is used for, about 188 million tons will not be offered for
recycling [2].
included not recycled metal”.
With this in mind we have analyzed the composition of the metal in
use and connected that
with the individual recycling rates.
Another remark about this mass model is that there is a clear
difference between the recycling
of process scrap (also called new scrap) and post consumer scrap
(called old scrap). This paper
is about utilizing the opportunities of post consumer scrap.
Figure 2: The not to be recovered fraction
While this potential of to be recycled material is building up
strongly, the actual recycling is still
far behind.
In 2008 about 8,7 million tons of post consumer scrap came
available to the market for
recycling. With the 452 million tons of metal in use, we can
continue recycling this way for the
coming 50 years and still that bubble of metal exists.
Nevertheless, the global aluminium recycling industry is racing to
gain ground. Every year
more post consumer scrap is recycled and besides that, process
scrap from new production is
also recycled.
This means that the potential for the aluminium recycling industry
is growing faster than the
potential for the primary aluminium industry.
Even with this development, large primary aluminium smelters are
under construction or
have started production recently in the Middle East, Iceland and in
Russia. Also other areas are
under investigation for the construction of mega-smelters such as
Africa and Asia.
These smelters have capacities sometimes exceeding 1 million tons
per annum, while not
long ago, the annual capacity of a good size primary smelter was
around 400 kilo tons.
On the other hand we see that, especially in Europe and North
America, the recycling
42 Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow?4
have gone bankrupt, into chapter 11 or simply disappeared from the
market.
Despite the future expectations and the closed capacity, we still
face a capacity utilization in
the recycling industry in the Western World of not more than
75%.
And if this bubble of metal in use will burst, the Western
countries do not have a recycling
industry that is up and ready to take on that enormous task,
despite the present capacity
utilization.
The large multi-national operating aluminium companies have never
shown much of a continual
interest in the aluminium recycling business, while it should be
expected that it is of strategic
last decades by the main players, but they never made it a
strategic issue.
The latest is that a few large aluminium companies are picking up a
renewed interest in the
aluminium recycling business. Time will tell if this interest is
sustainable this time.
The recycling industry is characterized by many smaller companies
scattered over the globe,
while the primary industry is in the hands of basically a few large
multi-nationals.
What will be the impact on the economical side of the business if a
fast growing primary
aluminium industry keeps supplying large volumes of metal, while on
the other hand recycling
of post consumer scrap should take off?
Volume-wise the perspective of recycling is far better. The
recycling industry is able to
supply metal for a far lower cost, that unfortunately is linked
nowadays to primary aluminium
prices.
Economical laws predict lower prices by a surplus of supply, but
what if, the recycling
industry comes under control of the primary business?
The primary industry is faced with high energy cost and the cost
will be rising eventually
while recycling could offer economical, environmental and feasible
alternatives?
To answer that, we have to look into the future market
developments. At present the industrialized
countries have an aluminium use (consumption) of more than 25kg to
32kg per capita. The
developing countries are far below that use on levels of 6-7 kg per
capita or even less. The
interesting question will be what the global need for aluminium
will be in e.g. 2050, knowing
that the world population will grow rapidly in the developing
countries and the aluminium use
per capita will increase accordingly.
Research based on the prediction of the growth of the world
population and the industrial growth
in the developing countries shows that the present production of
primary and recycled aluminium
together has to increase from the present 24 million tons per annum
to 70 million tons in 2050 to
keep pace with increasing demand en industrialization.
The present capacity of the primary industry is already about 30
million tons, thus a gap of
40 years. This underlines the enormous opportunity and challenge
for the global aluminium
recycling industry.
At present the recycling industry processes about 9 million tons of
post consumer scrap per
annum. If this volume can gradually be increased per year to 40
million tons, then in 2050 the
bubble of metal in use is still growing and has doubled over time.
But in the meantime we have
up scaled the recycling of aluminium post consumer scrap to a
respectable volume of 40 million
43Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow? 5
tons per year, stopped the increase in primary production of
aluminium and reduced the amount of
post consumer scrap with 1,1 billion tons. It would mean that
eventually the aluminium recycling
industry will take over the lead and the need for new primary
smelters would be reduced very
much. The future primary capacity would not need to exceed 30
million tons per annum.
Figure 3: prediction of aluminium consumption vs., increased
recycling production and stabilized primary production.
What does this mean for our environment? At present, per ton
primary aluminium 7,0 MT
greenhouse gasses (GHG) are emitted to the environment [3]. For
recycled post consumer scrap,
For the coming forty years we can reduce the emission of the global
aluminium recycling
industry by 22% if we indeed increase the recycling from post
consumer scrap according to the
proposed volume, compared with a situation whereby we increase our
primary capacity and
amounts up to 3 billion tons purely on the production of
aluminium.
The advantages are clear. Since recycling takes only a fraction of
the energy compared to the
primary produced metal, the energy need will be reduced
tremendously.
Of course it will increase the recycling of salts and dross, but
the total energy use will be
reduced to about 8 percent of the energy needed to produce primary
aluminium.
But just as important is that it will reduce greenhouse gasses on a
large scale, mainly in
production of aluminium but also in transport of aluminia and the
semi product to the customer.
With recycling there is a lot to gain on several fronts.
In Europe, 40% of produced aluminium comes from scrap, more than
any other region in the
world, although Asia is rapidly growing and catching up [4].
Recycling of aluminium reduces
greenhouse gas emissions by about 92 - 95 percent and that is why
this 40% should increase
strongly.
Europe, in other words the EU, should recognise the major role
aluminium recycling can play
burden on a sector that plays a vital role in improving
environmental performance.
44 Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow?6
Trading System ETS. Aluminium recycling offers a positive
contribution if it replaces primary
production.
If the situation with the aluminium primary and secondary industry
develop along as they
presently do, it is estimated that emissions avoided by the use of
post consumer scrap are up to
70 million tons of CO2 [5].
But if politicians and decision makers realise an increased
emphasis on the recycling of post
consumer scrap and minimising the growth of the primary aluminium
industry, the effect on our
environment will be far more massive and can sort a real difference
for the future.
But how is it possible that a marginal operating secondary
aluminium industry in the Western
have closed their doors because the realised margin’s have been to
meagre. Both continents are
still suffering from over capacity and the capacity utilisation
does not reach the 75% level. On
top of that they have to compete with primary smelters who are able
to realise better margins.
Unfortunately most of these secondary smelters are not recyclers in
the true sense of the
word. They mainly recycle process scrap from die casters, car
manufacturers and other users
of casting alloy. This process scrap is a clean scrap that does not
bear any risk in the recycling
process because it does not contain any foreign elements or
contamination. Actually this is not
recycling scrap but tolling process scrap into new metal.
Real aluminium recycling is the sorting, separation, preparation
and processing of post
consumer scrap and according to the earlier referred to Mass Flow
Model that volume is only
20% of all what is called aluminium recycling.
What the industry needs is the development of large recycling
plants (>50.000 tpa) that are able to
carry out the collecting, sorting and separation of post consumer
scrap with modern technologies
such as Eddy Current separation, X-ray transmission techniques and
laser induced break-down
spectrometer technology to assure the chemical composition of the
scrap. Further processing
Our European aluminium recycling industry is far from ready to
accept large volumes of
post consumer scrap and to process them under optimal conditions.
Also, volume-wise they
are not up to that enormous task at all. The same applies more or
less to the North American
aluminium industry.
Often the remark is made that nobody can estimate when this bubble
of post consumer scrap will
be available to the market, so why invest now for something that is
not available yet.
This is the wrong approach. There is already a large volume of post
consumer scrap available
but at present this is exported to Asia who has an industry capable
of processing post consumer
scrap. If the Western World would transform its aluminium recycling
industry into a true recycling
Europe and especially North America have many mines of scrap within
their borders that contain
From the early days of industrialization until very recently, large
volumes of used metals
raw materials for our industry.
45Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow? 7
One of the disadvantages of the aluminium success story is the
price of scrap. The scrap price is
related to the primary aluminium price. So if 70% aluminium can be
recovered from contaminated
post consumer scrap, the collectors ask 70% of the aluminium LME
notation, independent from
what they have paid themselves for the scrap. This has nothing to
do with the actual value, the
cost of preparing the scrap for remelting, or the price the
collector has paid for the scrap.
The primary aluminium price is very much depending on supply and
demand. It creates the
variations in pricing and this mechanism is also responsible for
the fact that sometimes the
aluminium price is below the cost price of primary smelters.
Usually a level of USD 2000/ton is
To link the aluminium scrap price to the primary aluminium price is
not correct, because it
reusable metal.
and investments in this part of the aluminium industry.
It is expected that when the focus is on recycling and the primary
industry does not have
principle of supply and demand.
fact that consumers should not have to pay for discarding their
garbage, because in most cases,
the contents are valuable. If consumers are paid for collecting
recyclable materials instead of
having to pay for its collection and disposal, it would stimulate
recycling rates enormously and
the cost would be paid by the value of the materials itself.
In conclusion, there are a few very good reasons to provide the
global aluminium recycling
industry with the room to expand and take a more important role in
the production of aluminium
semis.
The main reason is that when there are enough primary smelters in
the world to keep up with
the demand for primary metal, the secondary aluminium industry take
care of additional growth
of the market for aluminium and for increasing demand.
This means that the number of energy consuming and CO2 emitting
primary plants will
be limited and further demand will be supplied by low energy
consuming and low level CO2
emitting recycling plants.
This will reduce the intensive use of energy from the primary
process and the effective
reduction of emitting greenhouse gasses with 90%.
Therefore the output of the primary industry should be limited in
balance with the progressive
growth of the aluminium recycling industry to 40 million tpa, thus
reducing energy and CO2
emissions at an effective and large scale
This will create jobs, because aluminium recycling is a local
business, collecting the scrap locally
and making it available for the local industry which will increase
its use of aluminium because
of its contribution to a better environment. It makes no sense to
transport scrap to Asia, remelt it
there and ship it back to the Western World emitting even more
greenhouse gasses.
46 Frans Bijlhouwer / Will today’s Aluminium Recycling Industry be
the primary Industry of Tomorrow?8
References
[1]
[2] Remelt as major consumer of scrap. Metal Bulletin’s 17th.
International Recycled Aluminium Conference,
Bilbao, Ing. Frans Bijlhouwer MBA, 2009
[3]
[5]
1994
4711th International Aluminium Conference - ‘INALCO’ 2010 ‘New
Frontiers in Light Metals’ Laurens Katgerman and Frans Soetens
(Eds.) IOS Press © 2010 The authors and IOS Press
1
Abstract
Figure 1
48 Ulrich Knaack / Aluminium in Façades2
climate aspects into the façade technology; the result being
various variants of the double façade:
second-skin façade, box façade, corridor façade, and shaft-box
façade [4, 5, 6].
Current developments of such integrated façades, still focused on
energetic improvement, show
two tendencies: the so-called hybrid or mosaic façade, a
combination of a double façade with a
some or almost all building services components are integrated into
the façade itself, to comply
with the trend toward combining functions and to increase the
performance of the façade as an
industrial product [2,6].
the existing system. Common aluminium systems can be used as an
example: along with and
partially due to enhanced legal restrictions they have undergone
improvements in terms of their
thermal properties; yet, they still pose a critical problem for the
façade technology because on
one hand a physical contact between the inner and the outer shell
is necessary to enable load
transmission, but on the other a complete separation is desirable
in terms of building physical
possible, but there wi