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Acoustic Emission Monitoring Of In-Service Bridges, Theodore Hopwood Ii, David W. Prine
Acoustic Emission Monitoring Of In-Service Bridges, Theodore Hopwood Ii, David W. Prine
Kentucky Transportation Center Research Report
An experimental acoustic emission (AE) device, the GARD Acoustic Emission Weld Monitor (AEWM), has been field tested on six bridges during this study. In addition, the device was used to test three other bridges under separate contracts from state highway agencies. The device was evaluated to determine if it could detect fatigue-crack growth on in-service steel bridges.
The AEWM employs a proprietary three-step model (filter) to reject noise-related AE activity and detect and locate defects subject to varying stress conditions. The unit uses built-in microprocessors to compare incoming data to the model. If defect-related AE activity is detected, the AEWM …
Acoustic Emission Monitoring Of Bascule Bridge Components, Theodore Hopwood Ii
Acoustic Emission Monitoring Of Bascule Bridge Components, Theodore Hopwood Ii
Kentucky Transportation Center Research Report
During September 4-16, 1986, Kentucky Transportation Research Program (KTRP) personnel conducted a two-week inspection of welding operations on bascule bridge components for the Wisconsin Department of Transportation (WisDOT). Welding was performed by the Phoenix Steel Company at Eau Clair, Wisconsin. The inspection was conducted using acoustic emission (AE) monitoring on in-process welds.
KTRP investigative experience with AE weld monitoring and testing of bridges began in 1973. Since that date, KTRP has performed nine series of laboratory and fabrication shop weld monitoring tests and conducted 20 field tests of bridges using a series of increasingly sophisticated AE devices. Over the past …
Civil Engineering Applications Of Acoustic Emission, Theodore Hopwood Ii
Civil Engineering Applications Of Acoustic Emission, Theodore Hopwood Ii
Kentucky Transportation Center Research Report
In 1939, a suspension bridge at Portsmouth, Ohio, experienced stress-corrosion cracking of the main-cable wires at anchorage points located at each end of the bridge. Watchmen were placed in the anchor chambers where the fractures had been detected. Subsequently, they reported hearing the sounds of further wire breakage on quiet nights. When this was reported, a decision was made to recable the bridge (1). That was one of the earliest documented instances of the use of the acoustic emission phenomena in a structural application.
Also, in the late 1930's, L. Obert and W. I. Duval at the U. S. Bureau …