Optimized Biodynamic Shock Attenuation Performance Using an Adaptive Seat Suspension

Abstract

Design optimization-based techniques are presented for the minimization of biodynamic loads of a seated occupant subjected to a shock due to an initial velocity vertical impact. A 95th percentile male occupant was modeled using a multiple degree-of-freedom biodynamic lumped parameter model (BLPM) seated on a vertically stroking adaptive seat suspension with a semi-active magnetorheological energy absorber (MREA). The governing equations of motion of the adaptive MREA-based seat suspension with biodynamic lumped parameter model were developed. The variation of magnetorheological yield force with respect to the energy absorber stroke was shaped using cubic polynomial for the maximum shock attenuation. Three cost functions were devised with a common goal of minimizing biodynamic decelerations. Constraints were established based on limitation of MREA stroke and, yield force as well as stroking load. The MREA yield force and damper stroke were crucial parameters for improved biodynamic response mitigation to shock loads. A globally optimized biodynamic response was analyzed among several local optimum responses for better shock attenuation.