by Todd Hanson
When disasters like the recent bridge collapse in Minnesota occur, elected officials and the general public alike are often left wondering what can be done to avert such tragedies in the future.
In many cases, it often falls to America's national laboratories to research and develop advanced scientific and technical solutions to these issues of national safety and security.
In the case of the Minneapolis bridge collapse, engineers working in Structural Health Monitoring at Los Alamos National Laboratory's (LANL) Engineering Institute may already be well on their way to developing an engineering solution to the challenge of monitoring bridges.
Engineering Institute Director Chuck Farrar and his students are working on a technology using radio frequency identification (RFID)-based sensing, in-situ data analysis, and model-based reasoning for the rapid, economical, and reliable assessment of changes in and damage to large concrete and steel structures such as bridges.
One such RFID project is being developed by David Mascareñas, a doctoral student from the University of California-San Diego's Jacobs School of Engineering who is now working at the Engineering Institute. His project would use electronic sensors powered by microwaves to gather and send data via radiotelemetry to an airborne computer for analysis. In this case, the computer would be airborne thanks to a radio-controlled (RC) helicopter that Mascareñas has retrofitted to serve that function. Low-cost sensors placed on a bridge or similar architectural entity would detect electrical charges emitted by stress on materials, such as the steelreinforced concrete used to construct many bridges, and transmit the signals back to a receiver in the helicopter as it passes.
"Using RDIF and a RC helicopter, David has developed a potentially cheaper, safer, and easier way to monitor the structural health of our nation's bridges, which ultimately helps keep both bridge inspectors and the bridge users safer," said Farrar.
In 2006, Mascareñas became the first student in Jacobs School of Engineering to complete its new multidisciplinary degree program in structural health monitoring, damage prognosis, and validated simulations. The program is now one of several that are under the auspices of LANL's new National Security Education Center.
Structural health monitoring capitalizes on continuing advances in sensors, electronics, and communications to develop sophisticated technical and scientific methods for monitoring the condition, or so-called "structural health," of buildings, bridges, dams, and other important elements of the national infrastructure.
In the next several weeks, Mascareñas, Farrar and their research team will be traveling to a bridge near Truth or Consequences, New Mexico, to test the technology in the field. After that, it may someday be coming to a bridge near you.
A test flight of the mini-helicopter with its payload near Albuquerque, N.M. (Click image to enlarge)
