Speaker: Prof. Norman Wereley, University of Maryland at College Park, United States

Chair: Dr. Ramin Sedaghati

Abstract: The ability to dissipate energy in vehicle systems, especially with the goal of protecting occupants from potentially injurious vibration, repetitive shock, crash and blast loads, is becoming a critical issue as the cumulative impact of these load spectra on chronic health and acute injury are becoming better understood. The objective of this talk is to discuss what properties are optimal for energy absorption (EA) applications such as impact or shock load mitigation. Two primary strategies will be discussed in this talk: passive vs. semi-active energy absorbers. The first focus is the use of crushable materials to absorb energy. Two classes of passive materials will be discussed for EA applications including sintered and composite hollow glass foam materials, as well as elastomeric or plastic cellular materials. The second focus is the use of magnetorheological fluids (MRFs) or magnetorheological elastomers in EA applications. The properties of the MRF can be optimized for a particular application. A number of key nondimensional parameters can be used to gain insight into how to define optimality for various applications including: Bingham number, Hedstrom number, Reynolds number, Mason number, dynamic range. Also, the trade-offs associated in designing an optimal MRF for a particular application are discussed. The advantages of passive versus semi-active EA strategies will be discussed.