Featured Research

from universities, journals, and other organizations

Engineers Designing Smart Buildings To React To Shakes And Quakes

Date:
September 11, 1998
Source:
National Science Foundation
Summary:
Earthquakes, windstorms, traffic and explosives cause motion that can be catastrophic to buildings or bridges. National Science Foundation (NSF)-funded engineers Billie Spencer Jr. and Michael Sain at the University of Notre Dame are designing systems that counteract damaging structural responses to such events. These "smart buildings" adjust to changing conditions without requiring massive amounts of energy to do so.

Earthquakes, windstorms, traffic and explosives cause motion that can be catastrophic to buildings or bridges. National Science Foundation (NSF)-funded engineers Billie Spencer Jr. and Michael Sain at the University of Notre Dame are designing systems that counteract damaging structural responses to such events. These "smart buildings" adjust to changing conditions without requiring massive amounts of energy to do so.

Related Articles


"This type of research is important because it pioneers a novel concept for the optimal performance and safety design of buildings and other civil infrastructures, particularly those under the threat of earthquakes and other natural hazards," said Chi Liu, National Science Foundation program manager.

Acts of nature, terrorism or even traffic create ever-changing forces on most structures. Buildings rely primarily on strong materials and a structure that dissipates energy to resist damage. Increasingly, though, mechanical means are being explored.

Traditionally, buildings are built to sustain damage in order to survive during severe earthquakes, according to Spencer. "You wouldn't want that in your car -- for it to break every time you go over a pothole."

To prevent such damage, manufacturers put shock absorbers in the suspension of automobiles to dampen the effect of thumps and bumps. Engineers are using the same concept, to design shock absorbers for buildings. However, the best systems must adapt quickly to change.

"When controlling buildings during non-critical times, you want to have the dampers soft so there are no jerky movements, which helps protect the contents. But during an earthquake you want increased damping," Spencer said. In other words, during stable periods, building designers seek the soft, cushy, boat-like ride of a luxury car, but during a catastrophic event, they seek the tight-suspension control of a sports car.

The shock absorber Spencer and Sain are developing for use in buildings relies on the same premise as the shock absorber most used in cars with a piston in an air- or fluid-filled cavity. Unlike your car, however, the associated damping forces can be automatically adjusted.

Spencer and Sain's shock absorber uses an oil suspension of tiny iron particles. The viscosity of the fluid -- and the magnitude of the damping effect -- can be modulated by creating a magnetic field.

"The fluid is like water or a light oil, but when it is in the presence of a magnetic field it becomes thick like pudding," Spencer said. Sensors in the building can determine -- in real time -- the way the building is moving and modulate the damping forces on a series of the smart shock absorbers.

Another important feature of Spencer and Sain's system is that it requires very little power; each shock absorber requires only about 50 watts. The system could easily run on batteries, especially important during earthquakes where power is frequently interrupted.

In tests, a three-story structure exposed to the same forces as the 1940 El Centro earthquake showed that the magnetically adjusted shock absorber was much more effective than, for example, a shock absorber without any on-line provision for adjustment. The magnetically controlled damper reduced the peak effect of horizontal displacement and acceleration on the third floor by almost 75 percent and 50 percent, respectively. The displacement relates directly to the health of the building - if it is too large, the building may not return to its normal shape. The acceleration, on the other hand, relates to the protection and comfort of building occupants - forces which are felt by persons and which can be tolerated by expensive equipment.

Spencer and Sain are working with Lord Corporation to develop the details of the technology. They presented their work at several international conferences this past summer.

Editors: For more information, see: http://www.nd.edu/~quake/


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Engineers Designing Smart Buildings To React To Shakes And Quakes." ScienceDaily. ScienceDaily, 11 September 1998. <www.sciencedaily.com/releases/1998/09/980911074304.htm>.
National Science Foundation. (1998, September 11). Engineers Designing Smart Buildings To React To Shakes And Quakes. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/1998/09/980911074304.htm
National Science Foundation. "Engineers Designing Smart Buildings To React To Shakes And Quakes." ScienceDaily. www.sciencedaily.com/releases/1998/09/980911074304.htm (accessed October 31, 2014).

Share This



More Earth & Climate News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How A Chorus Led Scientists To A New Frog Species

How A Chorus Led Scientists To A New Frog Species

Newsy (Oct. 30, 2014) A frog noticed by a conservationist on New York's Staten Island has been confirmed as a new species after extensive study and genetic testing. Video provided by Newsy
Powered by NewsLook.com
Raw: Hawaii Lava Approaching Village Road

Raw: Hawaii Lava Approaching Village Road

AP (Oct. 30, 2014) The lava flow on the Big Island of Hawaii was 225 yards from Pahoa Village Road on Wednesday night. The lava is slowing down but still approaching the village. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Endangered Carpathian Ponies Are Making a Comeback in Poland

Endangered Carpathian Ponies Are Making a Comeback in Poland

AFP (Oct. 29, 2014) At the foot of the rugged Carpathian mountains near the Polish-Ukrainian border, ranchers and scientists are trying to protect the Carpathian pony, known as the Hucul in Polish. Duration: 02:17 Video provided by AFP
Powered by NewsLook.com
Deadly Mudslide in Sri Lanka Buries Houses

Deadly Mudslide in Sri Lanka Buries Houses

AP (Oct. 29, 2014) A mudslide triggered by monsoon rains buried scores of workers' houses at a tea plantation in central Sri Lanka on Wednesday, killing at least 10 people and leaving more than 250 missing, an official said. (Oct. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins