February 10, 2012
Recent earthquake damage has exposed the vulnerability of existing structures to strong ground movement. At the Georgia Institute of Technology, researchers are analyzing shape-memory alloys for their potential use in constructing seismic-resistant structures.
“Shape-memory alloys exhibit unique characteristics that you would want for earthquake-resistant building and bridge design and retrofit applications: they have the ability to dissipate significant energy without significant degradation or permanent deformation,” said Reginald DesRoches, a professor in the School of Civil and Environmental Engineering at Georgia Tech.
Georgia Tech researchers have developed a model that combines thermodynamics and mechanical equations to assess what happens when shape-memory alloys are subjected to loading from strong motion. The researchers are using the model to analyze how shape-memory alloys in a variety of components — cables, bars, plates and helical springs — respond to different loading conditions. From that information, they can determine the optimal characteristics of the material for earthquake applications.
February 4, 2012
To improve the next generation of insect-size flying machines, Johns Hopkins engineers have been aiming high-speed video cameras at some of the prettiest bugs on the planet. By figuring out how butterflies flutter among flowers with amazing grace and agility, the researchers hope to help small airborne robots mimic these maneuvers.
U.S. defense agencies, which have funded this research, are supporting the development of bug-size flyers to carry out reconnaissance, search-and-rescue and environmental monitoring missions without risking human lives. These devices are commonly called micro aerial vehicles or MAVs.
“For military missions in particular, these MAVs must be able to fly successfully through complex urban environments, where there can be tight spaces and turbulent gusts of wind,” said Tiras Lin, a Whiting School of Engineering undergraduate who has been conducting the high-speed video research. “These flying robots will need to be able to turn quickly. But one area in which MAVs are lacking is maneuverability.”