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.

Related Articles


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 March 31, 2015 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 March 31, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Tuesday, March 31, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dutch Architects Show Off 3D House-Building Prowess

Dutch Architects Show Off 3D House-Building Prowess

Reuters - Innovations Video Online (Mar. 31, 2015) Dutch architects are constructing a 3D-printed canal-side home, which they hope will spark an environmental revolution in the house-building industry. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Solar Plane Stops in China

Solar Plane Stops in China

Reuters - News Video Online (Mar. 31, 2015) Solar Impulse 2 stops over in China&apos;s Chonqing, completing the fifth leg in its bid to become the first solar powered plane to travel around the globe. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Solar Impulse Lands in China After 20-Hour Flight from Myanmar

Solar Impulse Lands in China After 20-Hour Flight from Myanmar

AFP (Mar. 31, 2015) Solar Impulse 2 lands in China, the world&apos;s biggest carbon emitter, completing the fifth leg of its landmark global circumnavigation powered solely by the sun. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
Bionic Ants Could Be Tomorrow's Factory Workers

Bionic Ants Could Be Tomorrow's Factory Workers

Reuters - Innovations Video Online (Mar. 30, 2015) Industrious 3D printed bionic ants working together could toil in the factories of the future, says German technology company Festo. The robotic insects cooperate and coordinate their actions and movements to achieve a common aim. Amy Pollock 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:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

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