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.

"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 July 25, 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 July 25, 2014).

Share This




More Earth & Climate News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
Powered by NewsLook.com
Higgins Breaks Record at Mt. Washington

Higgins Breaks Record at Mt. Washington

Driving Sports (July 24, 2014) Subaru Rally Team USA drivers David Higgins and Travis Pastrana face off against a global contingent of racers at the annual Mt. Washington Hillclimb in New Hampshire. Includes exclusive in-car footage from Higgins' record attempt. Video provided by Driving Sports
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:
from the past week

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