New Frontiers in Light Metals: Proceedings of the 11th International Aluminium Conference INALCO

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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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
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
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’.
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.
.
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.
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
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
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.
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
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.
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.
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.
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
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
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).
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
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
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.
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.
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)
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.
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.
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
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.
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
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
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.
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.
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.
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
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

New Frontiers in Light Metals: Proceedings of the 11th International Aluminium Conference INALCO

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