Featured Research

from universities, journals, and other organizations

Space Research Provides Earthshaking Revelations

Date:
October 6, 1997
Source:
National Aeronautics And Space Administration
Summary:
Research aboard the Space Shuttle is helping to provide a way to protect structures from major vibrations such as those produced by severe earthquakes and high winds.

Research aboard the Space Shuttle is helping to provide away to protect structures from major vibrations such as those producedby severe earthquakes and high winds.

Related Articles


Dr. Mark S. Whorton, an aerospace engineer at NASA's Marshall SpaceFlight Center, Huntsville, AL, has been working for several years onresolving vibration problems in a microgravity environment that can affectsensitive science experiments conducted aboard the Shuttle in orbit.

"Movements of the Shuttle, such as attitude corrections and theactivities of the crew members aboard the vehicle, create vibrations thatcan affect delicate experiments being conducted on board," he said."Solutions to reducing these minor vibrations in space also can be appliedto reducing the effect of major vibrations produced by earthquakes and high winds on terrestrial structures such as buildings and bridges."

Whorton has been conducting his research as part of his doctoralstudies program under Dr. Anthony J. Calise in the School of AerospaceEngineering at the Georgia Institute of Technology in Atlanta. The researchis part of a larger National Science Foundation effort to understand dynamicloads placed on structures by earthquakes and to identify ways of reducingtheir effect. The Georgia Tech research team for the past eight years hasbeen studying the benefits of using passive and active control strategies to reduce the effects of earthquakes on buildings.

"Technologies we've developed here at Marshall to protect experimentssuch as those involving crystal growth aboard the Space Shuttle are directlyapplicable to buildings and bridges during seismic events. Right now we'reworking on developing technological 'tools' which architects and constructionengineers can use when designing more earthquake-tolerant structures and inenabling existing structures to better survive earthquakes," Whorton said.

The National Science Foundation, under its program on EarthquakeHazards Mitigation in the Civil and Mechanical Systems Division, is funding amajor research program on structural control. Under this effort, the GeorgiaInstitute of Technology and other universities are involved in various aspectsof earthquake engineering such as developing better building materials, passivedamping methods, and active vibration control. Research activities at Marshallare focused in the area of active vibration control.

There are several ways to reduce the effect of structural vibrations.A direct approach is to stiffen the structure, which requires changing its massand therefore its vibration characteristics. While this may be acceptable formany terrestrial applications, the need for strong but lightweight structuresin space renders this option infeasible for NASA.

"Clearly, for applications in the space program, lightweight butequally effective vibration-mitigating alternatives were needed. We foundthat these technologies had down-to-Earth applications as well. One way ofcountering structural vibrations caused by a strong gust of wind or seismicground motion is to place sensors and force producing devices called actuatorsat specific locations on buildings. As sensors in the system measure themotion of the structure, actuators apply forces to counteract the structure'svibrations," Whorton said.

"One such force device would use hydraulic pistons moving counter-weights. Another method involves placing adjustable tendons along the sidesof structures. In fractions of a second, sensors in the systems can read thestructural vibration patterns caused by earthquakes or high winds and adjustthe tension on the appropriate tendons to reduce the excessive forces ormotions of the building," Whorton said.

All the actively controlled buildings in operation today are in Japanwith the exception of one in Taiwan. A TV tower in Nanjing, China, also is tobe retrofitted with active vibration control. Other new construction willincorporate the technology, particularly in seismically active regions; and itmay be possible to retrofit the technology to other existing structures.

"This technology -- in part derived from the nation's space program --is being adapted to meet the needs of the construction industry around theglobe," Whorton said. "The active control technology for vibration isolationis mature and is fully capable of doing the job. This is a technology readynow for commercial applications."


Story Source:

The above story is based on materials provided by National Aeronautics And Space Administration. Note: Materials may be edited for content and length.


Cite This Page:

National Aeronautics And Space Administration. "Space Research Provides Earthshaking Revelations." ScienceDaily. ScienceDaily, 6 October 1997. <www.sciencedaily.com/releases/1997/10/971006051031.htm>.
National Aeronautics And Space Administration. (1997, October 6). Space Research Provides Earthshaking Revelations. ScienceDaily. Retrieved January 26, 2015 from www.sciencedaily.com/releases/1997/10/971006051031.htm
National Aeronautics And Space Administration. "Space Research Provides Earthshaking Revelations." ScienceDaily. www.sciencedaily.com/releases/1997/10/971006051031.htm (accessed January 26, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Monday, January 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama's Wildlife Plan Renews Alaska Drilling Debate

Obama's Wildlife Plan Renews Alaska Drilling Debate

Newsy (Jan. 26, 2015) President Obama&apos;s proposal aims to protect more land in the Arctic National Wildlife Refuge, but so far, all that&apos;s materialized is a war of words. Video provided by Newsy
Powered by NewsLook.com
Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
Powered by NewsLook.com
Dramatic Footage Shows Coast Guard Rescue Off Scottish Coast

Dramatic Footage Shows Coast Guard Rescue Off Scottish Coast

Reuters - News Video Online (Jan. 23, 2015) Footage just released by the UK Coast Guard shows a dramatic helicopter rescue off the Scottish coast, where five men were plucked to safety after their fishing boat sank on Saturday. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Stunning Wingsuit Proximity Flying in Norway

Stunning Wingsuit Proximity Flying in Norway

Rumble (Jan. 23, 2015) A collection of amazing shots from flights made in the Aurland Valley in Norway. How incredible is that? Credit to &apos;BASEjumper&apos;. Video provided by Rumble
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