Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Virginia Tech engineers investigate energy independent monitoring system for bridges

13.02.2009
Virginia Tech's Center for Intelligent Material Systems and Structures (CIMSS) has teamed with Physical Acoustics Corporation (PAC), of Princeton Junction, N.J., to develop a suite of new technologies to provide a continuous, energy independent monitoring of the structural integrity of U.S. bridges.
The National Institute of Standards and Technology (NIST) funded the $14 million project, with Virginia Tech's share at about $2 million. The Federal Highway Administration (FHWA) estimates that more than 70,000 bridges in the United States are structurally deficient.

According to NIST, about 10,000 bridges are built, replaced, or rehabilitated annually, but that leaves a significant need for a system to provide continuously updated information on the structural health of the remaining bridges. The proposed system would provide the data needed to better prioritize repair operations and to notify bridge owners of extreme events such as collisions.

The system proposed by PAC and Virginia Tech, along with two additional research partners, the University of South Carolina and the University of Miami, will include an innovative research method for "harvesting" -- or securing -- its own power from motions and vibrations in the bridge using piezoelectric materials, thus making it "energy independent," said Dan Inman (http://www.me.vt.edu/people/faculty/inman.html), the director of CIMSS (http://www.cimss.vt.edu/) and the George Goodson Professor of Mechanical Engineering in Virginia Tech's College of Engineering (http://www.eng.vt.edu/main/index.php).

Piezoelectric materials are able to generate an electric potential when a mechanical stress in the form of vibration caused by traffic is applied.

According to Inman, the proposed instrument package will use acoustic emission sensing. When a crack or other flaw appears in a bridge, it emits acoustic waves. The sensors will detect these waves and monitor any changes.

The system is passive and non-destructive. The research targets both steel and concrete bridges.

The sensor data, transmitted through a wireless system, will feed computer models of the structure and a data interpretation system that will make assessments and predictions of the bridge's structural integrity on the basis of continuously updated information. Built-in self-check capabilities will eliminate the need for routine sensor maintenance.

The energy harvesting feature will eliminate the need for either a hard-wired power source for the hundreds of sensor nodes required or a reliance on batteries that would have to be regularly replaced. This aspect greatly reduces both installation and maintenance costs for the monitoring system, Inman added.

This NIST award is among the first under the agency's new Technology Innovation Program, created to support innovative, high-risk, high-reward research in areas of critical national need. NIST considers the high-risk elements of the proposal to include the development of the energy harvesting system, the sensors themselves, and the data interpretation, damage assessment, and health prognosis software.

Inman said that as "the inventory of bridges continues to age, routine inspection practices will not be sufficient for bridge owners to make informed decisions for safety and maintenance prioritization."

Continuous monitoring of the integrity of the bridge's structure is now needed. "The only feasible method is to allow engineers to observe various areas of concern such as a retrofit or a previous repair from a remote location. The monitoring can also be used as a preventative measure against terrorism or vandalism," Inman added.

Inman, who along with his students created a process allowing the use of smart materials to suppress and harvest vibrations, as well as the inventor of the self-sensing actuation principle for piezoceramic-based devices, explained this work will result in the use of a remote/online, self-powered global monitoring package, allowing for an early warning system. They say they plan to call it the Bridge Prognostic System, and it will be integrated into existing bridge management software to provide sound data for decision-making.

Multiple types of sensors will provide the information. "The primary advantage of the active sensing approach is that large areas can be scanned efficiently and cracks can be imaged remotely even though they are not actively growing," Inman said.

"It is clear from recent bridge collapses and the often reactive nature of bridge maintenance, that the major societal challenge of providing a safe and low-cost infrastructure system is not currently being met," Inman added.

Lynn A. Nystrom | Virginia Tech
Further information:
http://www.vt.edu

More articles from Architecture and Construction:

nachricht Smart buildings through innovative membrane roofs and façades
31.08.2017 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

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

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>