Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New ultrasonic technology could help prevent train derailments

22.08.2006
Researchers have developed a new technique they said is better able than currently used technology to find defects in steel railroad tracks

Researchers at the University of California, San Diego have developed a new technique they said is better able than currently used technology to find defects in steel railroad tracks, including hard-to-find internal cracks that can break under the weight of passing trains. Track defects account for about one-third of the 2,200 annual train derailments in the U.S., according to the Federal Railroad Administration (FRA), the federal agency charged with enforcing rail safety regulations.

A team led by UCSD structural engineering professor Francesco Lanza di Scalea describes in the Aug. 22 issue of the Journal of Sound and Vibration a defect-detection technique that uses laser beam pulses to gently "tap" on steel rails. Each laser tap sends ultrasonic waves traveling 1,800 miles per second along the steel rails. Downward facing microphones are positioned a few inches above the rail and 12 inches from the downward pointed laser beam. As the prototype vehicle rolls down the test track delivering laser beams taps at one-foot intervals, the microphones detect any telltale reductions in the strength of the ultrasonic signals, pinpointing surface cuts, internal cracks, and other defects.

In March 2006, Lanza di Scalea, project scientist Piervincenzo Rizzo and doctoral students Stefano Coccia and Ivan Bartoli tested a prototype vehicle equipped with the UCSD technology at a test track in Gettysburg, PA. The researchers detected 76.9 to 100 percent of internal defects and 61.5 to 90 percent of surface cuts in dry and wet conditions, respectively.

The UCSD team was supported by ENSCO, Inc., an engineering and technology company headquartered in Falls Church, VA, that develops inspection technologies for the Department of Transportation and other government agencies.

Lanza di Scalea and his team will test an improved design of their technology this fall in Gettysburg as part of an ongoing study funded by the FRA.

"Some of the worst derailments in this country have occurred on tracks recently inspected by the current generation of technology, which often doesn't detect interior cracks in rails that happen to lie under areas of superficial cracking," said Lanza di Scalea. "Our technique is much better able to find such defects, and it can work under varying weather conditions while the inspection vehicle is zipping along a track at speeds of up to 70 mph."

Rail carriers moved 42 percent of America's total coal, chemicals, minerals, food and other goods shipped in 2005, according to the U.S. Department of Transportation. Track-related damage from derailments and other incidents doubled from $55 million in 1993 to $111 million in 2000, and the trend toward longer trains pulling heavier cars at higher speeds creates the potential for even greater losses.

The current generation of track-inspection technologies relies on a variety of techniques, including water-filled wheels or sleds that move over track surfaces at roughly 30 mph while sending ultrasonic pulses downward into the track. The inaudible ultrasonic pulses reflect back as echoes when they encounter cracks. Unfortunately, the signals are routinely blocked by superficial surface cracks from detecting more dangerous internal cracks.

Surface cracking does not interfere with the movement of ultrasonic pulses in the UCSD technology. "The ultrasonic sound we use doesn't come from the top of the rail, but instead travels along the rail," said Lanza di Scalea. "Our pulsed-laser technique, combined with ultrasonic microphones positioned a few inches above the rails and sophisticated software that filters out noise and other sources of variability is potentially very effective at finding internal rail defects."

Rex Graham | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Transportation and Logistics:

nachricht Variable speed limits could reduce crashes, ease congestion in highway work zones
07.06.2017 | University of Missouri-Columbia

nachricht Experiments show that a few self-driving cars can dramatically improve traffic flow
10.05.2017 | University of Illinois College of Engineering

All articles from Transportation and Logistics >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>