TEST YOUR METALS THE BLAST MACHINE

摘要

If you need something blown up for science, call Arun Shukla. At his University of Rhode Island lab, the mechanical engineer simulates the shock waves, temperatures, and extreme pressure loads that a Navy submarine or an Air Force jet might encounter in combat, and looks at how their structures come apart. "Our experiments are designed to understand the physics of deformation and why things break," Shukla says. One of his handiest tools is a shock-tube apparatus, which replicates explosive blasts and their effect on metal alloys, composites, and glass. An experiment using the 40-foot-long megablaster takes all of 5 milliseconds, but it requires a full day of setup and a warning to the building about the forthcoming bang. "Every time it goes off I get excited," Shukla says. "If the experiment is successful, then I get more excited." Shukla then uses data from high-speed cameras to create three-dimensional images of the target as it deforms, shatters, cracks, or disintegrates. In his analysis, he looks for where the damage started, how it spread, and where the weak and strong points in the structure are. The military uses these findings "in applications we may never learn about," Shukla says. That's not his problem-he'll be concentrating on the next kaboom.