Energy Absorption and Recovery in Tapered Granular Chains: Small Chains and Low Tapering

Abstract

Shock absorption traditionally exploits visco-elastic devices, fluid viscous dampers and friction dampers, or “soft” materials. Recent work on impulse propagation in granular assemblies suggests that it may be possible to absorb shock waves using a different variety of shock absorbers and thus unlock the possibility of building structures that are significantly more shock absorbent than is currently possible, an issue of relevance to concerns of security. These new shock absorbers are composed of granular materials and exploit the nonlinear energy propagation properties in assemblies of granular materials. They have the potential to partially recover the energy of the absorbed shock waves for useful purposes, a property that might allow one to design devices to convert the incident energy to other useful forms. The basic physics of the “tapered chain shock absorber” is briefly discussed in this work.

Shock dynamics in granular chains: numerical simulations and comparison with experimental tests

“…This kind of granular chains has been extensively investigated analytically, numerically and experimentally [12,17,34,36,44,52,54,58]. Tapered chains show interesting mechanical features such as the dispersion effect and the capability of shock absorption.…”

“…chains with decreasing size of the beads [12,17,44,52,54,58]; (4) stepped chains, i.e. chains composed of a large monodisperse section followed by a small monodisperse section [23,38]; (5) decorated chains with small masses placed regularly or randomly among larger masses [15,18,19]; (6) composite chains, i.e.…”

Numerical Simulation of a Novel Blast Wave Mitigation Device

“…It was found that density, porosity and relative geometrical size of the so-called ''soft'' condensed matter are the main parameters determining the effectiveness of blast wave mitigation. Pfannes et al [3] investigated a tapered chain of elastic beads under impulse loading. The elastic beads act as an absorber of kinetic energy or impulse and can reduce it by about 30%.…”

Experimental Investigation of a Novel Blast Wave Mitigation Device

“…The density, porosity and relative geometrical size of the so-called "soft" condensed matter are the main parameters determining the effectiveness of blast wave mitigation. Pfannes et al [10] investigated a tapered chain of elastic beads under impulse loading. The elastic beads act as an absorber of kinetic energy and can reduce it by about 30%.…”