The development of a long-term electrolyte gel will enable MFS to test for cracks in bridges over the long-term, lasting months instead of days. MFS would offer this enhanced EFS System as part of an overall long-term bridge monitoring system, many of which are being implemented across the country. Typically, these ongoing monitoring systems include video cameras, weight and temperature sensors, and other technologies to ensure vehicle safety and provide the bridge owner with extensive knowledge of bridge status.
Electrochemical Fatigue Sensor
The technology behind EFS was originally devised by researchers for the U.S. Air Force and the University of Pennsylvania for use in the aerospace industry. The original research was aimed at developing a technology for detecting problem cracks in airframes and engines.
Since that time, additional research and development has resulted in the adaptation of the EFS system for steel bridge inspection. In 1993, they forged a development deal with MFS, which revamped the technology for bridge inspections between 2002 and 2006.
To use the EFS on bridges, inspectors first identify the vulnerable parts of a bridge. These could be the areas most susceptible to wear and tear — say, a sharp corner or a welded connection — or places where bridge owners already suspect a crack.
Then they wire up the areas with sensors, which are similar to the peel-and-stick versions used for an EKG reading. Finally, they apply a constant electrical current that runs between the sensors and the bridge.
By assessing the behavior of the current as it passes through the metal, the sensors can detect cracks down to a hundredth of an inch in size. And because the device is operated while the bridge is in use, it can determine how the cracks change as the structure flexes under stress. MFS’s software analyzes the resulting data to determine whether cracks are staying the same size or growing.