Dr. Michelle Manuel, chair of the Department of Materials Science Engineering, and her team of researchers explored the use of infrared ultra-time-domain (IR-UTD) testing as an improved method of inspecting bridge welds. Steel bridges are created by welding steel components. The quality of these welds is critical to the integrity of the bridge. Weld defects can lead to expensive repairs or mechanical failure. However, weld defects are often below the steel surface and in places that are difficult to reach; therefore, the search for improved methods of weld inspection is ongoing. The primary goal of the researchers was to understand the sensitivity of IR-UTD testing to specific types of defects. IR methods work by observing patterns of heat on the steel surface as the steel is heated. Changes in these patterns can reveal underlying defects, but the patterns can also be affected by the type and location of the heat source. Therefore, to investigate the changes in thermal patterns, it was necessary to test a variety of defects exposed to a variety of heat sources. (Source: FDOT project summary)