Novel simulation
technology supports ground-breaking
research into wind effects on homes
and low-rise buildings
*
world's first realistic home simulation
facility – ‘The Three
Little Pigs’ - will deliver
better protection against extreme
weather
* research
targets huge global problem - weather
damage costs £700m pa in the
UK alone and hurricane damage is typically
measured in billions
Pioneering Canadian research into
wind effects on low-rise buildings
will use novel wind simulators being
developed by Cambridge Consultants.
A new University of Western Ontario
research centre - known as ‘The
Three Little Pigs’ facility
– will, for the first time,
permit the controlled application
of realistic wind loads to full-scale
houses and other low rise buildings.
The research
is expected to lead to more formalised
techniques for weather-proofing low-rise
buildings which - unlike their high-rise
counterparts - are ‘non engineered’
and tend to use vaguely-defined structures.
The research will help to deliver
protection against evolving weather
hazards by providing the know-how
to improve building codes and quality
control strategies.
"No one
has attempted real-world wind simulation
on this scale before, so much of the
instrumentation will be developed
specially for the application",
says Eric Wilkinson, head of Cambridge
Consultants' Products and Systems
Business Unit. "One of the key
challenges is the creation of a custom
control system architecture to handle
the large number of interconnected
wind simulators, and deliver the real-time
performance required."
Realistic
wind simulation will be provided by
pressure boxes that are able to apply
positive or negative wind forces over
a +5 to -20 kilopascals range (5 kilopascals
equates to a weight of around 500kg
for every square metre of roof). This
is combined with a fast-acting valve
system that allows the simulated wind
pressure to reverse direction at rates
up to seven times a second. The University
of Western Ontario's deep understanding
of wind patterns will use this technology
to create and apply realistic ‘wind
profiles’ onto full-size structures
- beginning with a full-size two-storey,
pitched-roof dwelling. Surrounding
the space for test structures is a
reaction frame, which provides mountings
for the pressure boxes. All this equipment
will be housed in a hangar-style building
large enough to accommodate structures
of up to three storeys, and which
slides on rails to expose structures
to the natural environment.
Cambridge
Consultants won the development contract
because of its unique expertise in
this area, gained from work in the
late 1980s on the UK Building Research
Establishment (BRE) ‘Brerwulf’
project. At that time, working to
a BRE design concept, the consultancy
developed a large fan-driven wind
simulation panel - measuring around
3 metres square - which provided a
mechanism to test roofing systems
and cladding.
The same basic
wind generation technology - which
uses high-performance fans - will
be used in ‘The Three Little
Pigs’ pressure boxes. However,
for this application, a modular range
of box sizes is being developed to
enable complex building shapes to
be handled. Each box will additionally
feature a sophisticated control and
networking system that will allow
the complex time- and spatially-varying
wind effects of the real world to
be realistically applied. This scheme
will allow up to 100 interconnected
pressure boxes to be controlled in
real-time, supporting system sizes
large enough to test complete low-rise
buildings.
The leading
wind-engineering consultancy RWDI-Anemos
- whose Director Nicholas Cook was
one of the designers of the seminal
Brerwulf project - is helping Cambridge
Consultants to develop the new pressure
boxes and control scheme, by providing
expert local advice on wind loading
effects.
Paul Freathy,
Managing Director of RWDI-Anemos,
comments: "Damage to non-engineered
buildings remains a significant financial
burden on the economy. Although individual
incidents are often minor, insurance
statistics show that weather damage
averages out to about £700 million
per year in the UK alone. RWDI Anemos
is delighted to be able to contribute
to this important research project;
using our knowledge of the Brerwulf
concept and expertise in wind loading
and failure studies to help develop
better buildings for the future."
Dr Michael
Bartlett, Associate Professor at The
University of Western Ontario and
Principal Investigator of ‘The
Three Little Pigs Project’,
comments: "The entire research
team is delighted to be working with
Cambridge Consultants. We are confident
that with the combination of Cambridge
Consultants and RWDI-Anemos we are
working with the most qualified group
in the world to develop this complex
system."
Cambridge
Consultants will deliver the wind
simulation pressure boxes in mid 2005.
To download high resolution images
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Notes
for editors:
The Three Little Pigs Project
at The University of Western Ontario
(London, Ontario, Canada).
In 1992, Hurricane Andrew hit south
Florida, destroying 20,000 houses
and causing US $30 billion in damage.
If the storm had tracked 50 km further
north, estimated damage would have
exceeded US $100 billion. The Three
Little Pigs facility will permit,
for the first time anywhere, the application
of realistically simulated time and
spatially varying wind loads to full-scale
houses and light-frame structures
including sheet steel buildings, in
a controlled manner, up to failure.
This will permit an assessment of
the integrity of the overall structure
of the building, the pathways by which
the load is transmitted through the
structure to the ground and the performance
of individual building components
as part of the whole construction.
Simulated snow loading will also be
investigated. In addition, the facility
will be used to assess the factors
influencing the ingress of moisture
due to wind-driven rain and the development
of harmful mould growth under realistic
environmental conditions. Further,
information on human error during
the construction process will be collected
and its impact on the potential damage
and failure will be analyzed. These
will all be breakthrough developments
to the current state-of-the-art.
Houses
and light-frame buildings are complex
structures because of their highly
redundant and vaguely defined structural
systems. For example, resistance to
lateral movement is largely derived
from the drywall nailed to both load-bearing
and non load-bearing walls inside
the structure. The infrastructure
will generate necessary data to validate
the next generation of computational
analyses of houses and light frame
buildings that will accurately predict
behaviour up to failure. Full-scale
component tests and even the static
loading of complete structures do
not adequately predict true behaviour
under transient peak wind loads that
fluctuate dramatically over the surface
of the building. Thus, the precise
response mechanisms up to failure
are not yet known.
The
goal of this research is to develop
anticipatory mitigation strategies
to protect people’s homes from
destructive environmental forces,
by: (1) modifying building codes to
advance safer, yet less expensive
houses; (2) working with the insurance
industry and government to develop
implementation strategies; (3) developing
cost-effective mitigation devices
for retro-fitting the existing housing
stock; and (4) developing quality-control
strategies to minimize human error
in construction.
This
material is taken from www.eng.uwo.ca/research/ttlpp/.
A more detailed description may be
found there.
The
University of Western Ontario (London,
Ontario, Canada) is a vibrant
centre of learning with more than
1,700 faculty members and 32,000 undergraduate
students. Through its 12 Faculties
and Schools, and three affiliated
colleges, the University offers more
than 60 different degree and diploma
programs. Research is an integral
part of the University’s mission,
and Western is home to one of Canada’s
strongest research constellations
in the area of biomedical research.
With nearly $190 million in annual
funding, Western ranks as one of the
top research intensive universities
in Canada. www.uwo.ca
Cambridge
Consultants has for over
40 years enabled its clients to turn
business opportunities into commercial
successes, whether launching first-to-market
products, entering new markets or
expanding existing markets through
the introduction of new technologies.
With a team of over 200 engineers,
scientists and consultants in offices
in Cambridge (UK) & Boston (USA),
it is able to offer solutions across
a diverse range of industries including
healthcare, industrial & consumer
products, automotive, transport, energy
& wireless communications.
RWDI-Anemos
Consulting Engineers is one
of the UK’s leading wind engineering
consultancies and part of the RWDI
Group, the largest such consultancy
in the world. Its expertise lies in
solving construction design and performance
problems relating to the effect of
wind on buildings and the environment,
as well as the design and performance
of construction products. The company,
which boasts more than 100 years’
combined industry experience, including
work on the world’s tallest
buildings, also offers training in
the principles of wind-engineering,
the appropriate use of codes of practice
and software development. www.rwdi-anemos.com
