Blacksburg, Va. 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, the director of CIMSS and the George Goodson Professor of Mechanical Engineering at Virginia Tech.
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 (AE) 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
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