Featured Research

from universities, journals, and other organizations

Ultrasound Method Diagnoses Stress Before Bridges Crack

Date:
May 14, 1998
Source:
National Institute Of Standards And Technology (NIST)
Summary:
NIST scientists are using ultrasound to measure the change in stresses on pin and hanger assemblies found on bridges. Their goal is to develop a method for assessing the status of these connections.

NIST scientists are using ultrasound to measure the change in stresses on pin and hanger assemblies found on bridges. Their goal is to develop a method for assessing the status of these connections.

In a typical situation, a pin and hanger connection is used to suspend an inner span from an outer support span; it also accommodates thermal expansion. But because the connection is located at the expansion joint, road deicing salts may wash down through the joint and cause corrosion at the pins. If the corrosion is sufficient to lock up the pins, it can cause additional forces on the connection, leading to fatigue cracking and eventual failure.

NIST is experimenting with an ultrasound technique, which has the potential to determine connection stress prior to development of fatigue cracks. To evaluate its method, NIST designed and constructed a pin and hanger simulation facility at its Boulder, Colo., laboratories. Strain gauges were mounted on the hangers, and the strains were measured as load was applied. At the same time, ultrasonic measurements were made at the gauge locations.

Strains were predicted from the ultrasonic data and compared with values measured by the strain gauges. "Overall good agreement was obtained between ultrasonic and strain gauge results," the scientists report.


Story Source:

The above story is based on materials provided by National Institute Of Standards And Technology (NIST). Note: Materials may be edited for content and length.


Cite This Page:

National Institute Of Standards And Technology (NIST). "Ultrasound Method Diagnoses Stress Before Bridges Crack." ScienceDaily. ScienceDaily, 14 May 1998. <www.sciencedaily.com/releases/1998/05/980514080415.htm>.
National Institute Of Standards And Technology (NIST). (1998, May 14). Ultrasound Method Diagnoses Stress Before Bridges Crack. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/1998/05/980514080415.htm
National Institute Of Standards And Technology (NIST). "Ultrasound Method Diagnoses Stress Before Bridges Crack." ScienceDaily. www.sciencedaily.com/releases/1998/05/980514080415.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. 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