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Mitigation of Blast, Impact, and Vibration: From Energy Dissipation to Energy Capture
Date: 2014/12/30             Browse: 484

Speaker: Weiyi Lu

Time: Dec. 30, 3:15-4:45pm

Location: Room 220, Building 8, Yueyang Road Campus

Abstract:

Blast attack, impact, earthquakes, and vibrations are major threats to engineering structures, vehicles, and key personnel. Recently, we developed a novel, nanoporous materials functionalized (NMF) liquid that can react within microseconds to sufficiently reduce stress waves.

An NMF liquid is a liquid suspension of nanoporous particles in a liquid phase. The inner nanopore surface is specially treated so that it is non-wettable to the liquid. Under ambient condition, due to the capillary effect, the nanopores remain empty. At a blast wave front, the local high pressure can rapidly compress the liquid into the nanopores, converting a significant amount of energy into heat as well as interfacial tension, due to the ultra large specific surface area of the nanoporous materials. Moreover, the small ligament length and the effective multilayer structure of large impedance mismatch enable a high-efficiency energy capture mechanism, as the wave energy transmission paths are interrupted.

The performance of the NMF liquid was characterized in a broad range of strain rates, from quasi-static compression tests to live blast experiments. At higher strain rates, the energy absorption capacity of the NMF liquid was several orders of magnitude larger than the value under quasi-static loadings, indicating other novel protection mechanism is associated with this system.

Bio:

Dr. Weiyi Lu is an Assistant Professor in the Department of Civil and Environmental Engineering at Michigan State University. Before he joined MSU he was a postdoctoral scholar in Department of Structural Engineering at University of California, San Diego. He received his Ph.D. degree in 2011 from Department of Structural Engineering at University of California, San Diego. He received his M.S. and B.S. degrees from Shanghai Jiao Tong University in 2007 and 2004, respectively. He has published 30+ papers in peer-reviewed journals. His research is focused on advanced nanoprous materials, novel energy mitigation mechanisms, multifunctional engineering materials and structures, and high-strain-rate behavior of materials.                                                                                                                                                                                  

                      SIST-Seminar 14047