Research and answer the following questions:
How are gravitational field maps used to correct errors in navigational systems used in unmanned underwater vehicles (UUVs)?
How are magneto-rheological (MR) fluid dampers used in buildings to absorb the shocks from earthquakes?
How can radio frequency identification (RFID) chips be used for inventory tracking in stores and warehouses?
Answers
The magnetorheological-fluid dampers are shock-absorbing devices containing a liquid that becomes far more viscous when a magnetic field is applied.
"It normally feels like a thick fluid, but when you apply a magnetic field it transforms into a peanut-butter consistency, which makes it generate larger forces when pushed through a small orifice," said Shirley Dyke, a professor of mechanical engineering and civil engineering at Purdue University.
This dramatic increase in viscosity enables the devices to exert powerful forces and to modify a building's stiffness in response to motion during an earthquake. The magnetorheological-fluid dampers, or MR dampers, have seen limited commercial use and are not yet being used routinely in structures.
Research led by Dyke and doctoral students Gaby Ou and Ali Ozdagli has now shown real-time hybrid simulations are reliable in studying the dampers. The research is affiliated with the National Science Foundation's George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a shared network of laboratories based at Purdue.
Dyke and her students are working with researchers at the Harbin Institute of Technology in China, home to one of only a few large-scale shake-table facilities in the world.
Findings will be discussed during the NEES Quake Summit 2013 on Aug. 7-8 in Reno. A research paper also was presented in May during a meeting in Italy related to a consortium called SERIES (Seismic Engineering Research Infrastructures for European Synergies). The paper was authored by Ou, Dyke, Ozdagli, and researchers Bin Wu and Bo Li from the Harbin Institute.
"The results indicate that the real-time hybrid simulation concept can be considered as a reliable and efficient testing method," Ou said.
The simulations are referred to as hybrid because they combine computational
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