Featured Research

from universities, journals, and other organizations

Singing Screws Reveal Sick Structures

Date:
April 29, 2009
Source:
American Institute of Physics
Summary:
In 2006, a concrete panel weighing several thousand pounds fell onto traffic in Boston's Big Dig tunnel, crushing a car and killing a motorist. The alleged cause -- and subject of a multi-million dollar settlement -- was faulty epoxy that allowed bolts in the ceiling to wiggle loose.

In 2006, a concrete panel weighing several thousand pounds fell onto traffic in Boston's Big Dig tunnel, crushing a car and killing a motorist. The alleged cause -- and subject of a multi-million dollar settlement -- was faulty epoxy that allowed bolts in the ceiling to wiggle loose.

Mechanical engineer Joe Guarino of Boise State University in Idaho is developing an early warning system to prevent such catastrophic joint failures in the future. His team listens to the sounds made by vibrating bolts. Their analysis of how these sounds change as the bolts unscrew has revealed certain frequencies in these noises that could be monitored to check the health of bolts in buildings, bridges, and tunnels.

Guarino and his team work on a full-scale structural model made of steel beams and girders connected by bolts. They tap the structure with a hammer, causing it to vibrate. The sounds made by the vibrating bolts are recorded by an electronic stethoscope, similar in design to the stethoscopes used by doctors. Then the engineers unscrew the bolts a bit, tap the structure again, and listen for changes in the sounds. "Any slight relaxation in a joint can change the way it vibrates," says Guarino.

Using a pattern detection technique called the continuous wavelet transform, the team can pick out which ranges of frequencies change the most. Their results suggest that the signatures of unscrewing may be found in certain mid-to-high frequencies. During the talk, Guarino will be explaining and playing these sounds, available for use by the press.

The research is still in the preliminary stages of lab testing. But Guarino hopes to eventually take it into the field to check for bolts that are vibrating loose or degrading through exposure to the elements. "If we're successful, this could lead to implanting permanent, inexpensive accelerometers that could monitor joints continuously," says Guarino.

The talk "Acoustic detection of bolt detorquing in structures" by Joe Guarino will be presented at the 157th  Acoustical Society of America Meeting to be held May 18-22 in Portland, Ore.


Story Source:

The above story is based on materials provided by American Institute of Physics. Note: Materials may be edited for content and length.


Cite This Page:

American Institute of Physics. "Singing Screws Reveal Sick Structures." ScienceDaily. ScienceDaily, 29 April 2009. <www.sciencedaily.com/releases/2009/04/090426094254.htm>.
American Institute of Physics. (2009, April 29). Singing Screws Reveal Sick Structures. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2009/04/090426094254.htm
American Institute of Physics. "Singing Screws Reveal Sick Structures." ScienceDaily. www.sciencedaily.com/releases/2009/04/090426094254.htm (accessed September 17, 2014).

Share This



More Matter & Energy News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

MIT's Robot Cheetah Unleashed — Can Now Run, Jump Freely

Newsy (Sep. 16, 2014) — MIT developed a robot modeled after a cheetah. It can run up to speeds of 10 mph, though researchers estimate it will eventually reach 30 mph. Video provided by Newsy
Powered by NewsLook.com
Manufacturer Prints 3-D Car In Record Time

Manufacturer Prints 3-D Car In Record Time

Newsy (Sep. 15, 2014) — Automobile manufacturer Local Motors created a drivable electric car using a 3-D printer. Printing the body only took 44 hours. Video provided by Newsy
Powered by NewsLook.com
Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Refurbished New York Subway Tunnel Unveiled After Sandy Damage

Reuters - US Online Video (Sep. 15, 2014) — New York officials unveil subway tunnels that were refurbished after Superstorm Sandy. Nathan Frandino reports. Video provided by Reuters
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