Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Space Industry and Business News .




TECH SPACE
Researchers tackle collapsing bridges with new technology
by Staff Writers
London, UK (SPX) May 03, 2013


The Tacoma Narrows Bridge is perhaps the most famous example of a bridge that collapsed in response to external forces. In 1940 strong rhythmic cross-winds resonated with the bridge's natural frequency, causing it to bend and twist until it collapsed.

An international group of researchers propose a new technology that could divert vibrations away from load-bearing elements of bridges to avoid catastrophic collapses.

In this month's issue of Physics World, an international group of researchers propose a new technology that could divert vibrations away from load-bearing elements of bridges to avoid catastrophic collapses.

Michele Brun, Alexander Movchan, Ian Jones and Ross McPhedran describe a "wave bypass" technique that has many similarities to those being used by researchers looking to create Harry Potter-style invisibility cloaks, which exploit man-made materials known as metamaterials to bend light around objects.

Led by Movchan, who is at the University of Liverpool, the researchers propose making "lightweight changes" to existing bridges by bolting on special lightweight structures at period intervals to the underside of the main "deck" of the bridge. These structures would consist of concentrated cubic blocks, or resonators, linked to each other, and the bridge, by a series of bars.

The resonators, appearing under the bridge like a set of hanging baskets, could be fine-tuned to the specific vibrations that make a bridge susceptible to collapsing, meaning the vibrations get redirected into the resonators and make the bridge safer.

The Tacoma Narrows Bridge is perhaps the most famous example of a bridge that collapsed in response to external forces. In 1940 strong rhythmic cross-winds resonated with the bridge's natural frequency, causing it to bend and twist until it collapsed.

Although 21st-century structures are much more robust, the researchers' proposals have been inspired by events on the Volga Bridge two years ago.

The 7.1 km bridge, which crosses the river Volga in Russia, was forced to shut in May 2011 - less than a year after opening - when a long-wavelength resonance vibration caused sections of the bridge to bend. A similar problem struck the Millennium Bridge in London when it first opened in 2000.

"Even though the Volga and Millennium bridges were designed using industry-standard packages, the fact that problems arose shows that it is all too easy with large and complicated structures to overlook vibrations that may cause structural problems under practical conditions," the researchers write.

The concept of a wave bypass is also found widely in nature, specifically in certain moths and butterflies, which have remarkable nanostructures that create diffracting mirrors. The mirrors funnel light of a desired colour into a vivid optical display on the organism's body.

"It is, to us, remarkable that the principles lying behind structured mirrors, waveguides and bypass structures can be used not just by the humble sea mouse for its iridescence but also by engineers in the quest for more resilient and robust bridges," the researchers write.

.


Related Links
Institute of Physics
Space Technology News - Applications and Research






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





TECH SPACE
Microgels' behaviour under scrutiny
Heidelberg, Germany (SPX) May 03, 2013
Being a physicist offers many perks. For one, it allows an understanding of the substances ubiquitous in everyday industrial products such as emulsions, gels, granular pastes or foams. These are known for their intermediate behaviour between fluid and solid. Paint, for example, can be picked up on a paintbrush without flowing and spread under the stress of the brush stroke like a fluid. Ba ... read more


TECH SPACE
NASA Partners With Utah State University's Space Dynamics Lab

Silicone liquid crystal stiffens with repeated compression

Researchers tackle collapsing bridges with new technology

Penn Research Helps to Show How Turbulence Can Occur Without Inertia

TECH SPACE
Department of Defense looking to allow Apple, Samsung devices

DARPA Seeks Clean-Slate Ideas For Mobile Ad Hoc Networks

Astrium's secure milsatcoms now cover the world

Gilat to Equip IDF with SatTrooper-1000 Military Manpack

TECH SPACE
Checkout is underway with O3b Networks' four satellites to be orbited on the next Arianespace Soyuz launch

The Well-Built Italian

O3b Networks' first four satellites arrive for the next Arianespace Soyuz launch

On the record with... Stephane Israel, Arianespace Chairman and CEO

TECH SPACE
Spatial Dual Offers Dual Antenna For GNSS/INS

Raytheon completes second launch exercise for next generation GPS satellites

Sagetech Delivers NextGen Technology for Satellite Constellation

Northrop Grumman to Demonstrate Open Architecture Navigation System for DARPA

TECH SPACE
Australia unveils its F-35 JSF 'Iron Bird'

China welcomes French president with Airbus deal

Multifunction Advanced Data Link Flight Tested For F-35 Program

Brazil drops plan to build AgustaWestland helicopter

TECH SPACE
New Method Joins Gallium Nitride and Diamond for Better Thermal Management

Intel names insider Krzanich as new CEO

High performance semiconductor spray paint could be a game changer for organic electronics

New Research Findings Open Door to Zinc-Oxide-based UV Lasers, LED Devices

TECH SPACE
World's major development banks look closer at Earth observation

China Successfully Sends First Gaofen Satellite Into Space

China launches high-definition earth observation satellite

Japan's Mt Fuji to get World Heritage stamp: officials

TECH SPACE
Hong Kong struggles to combat waste crisis

Hundreds protest China chemical plant: Xinhua

Lake Found in Sierra Nevada with the Oldest Remains of Atmospheric Contamination in Southern Europe

Researchers pinpoint how trees play role in smog production




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement