Eur. Phys. J. E (2014) 37: 119
https://doi.org/10.1140/epje/i2014-14119-9

Regular Article

A quasi-unidimensional granular chain to attenuate impact

¹ Núcleo de Desevolvimento Amazônico em Engenharia, NDAE, Universidade Federal do Pará, Caixa Postal 479, 68464-000, Tucuruı, PA, Brazil
² Departamento de Física, CCEN, Universidade Federal da Paraıba, Caixa Postal 5008, 58059-900, João Pessoa, Brazil
³ Department of Chemistry and Biochemistry, University of California San Diego, 92093-0340, La Jolla, California, USA

^* e-mail: arosas@fisica.ufpb.br

Received: 14 August 2014
Revised: 16 October 2014
Accepted: 3 November 2014
Published online: 25 November 2014

Abstract

We study via numerical simulations a granular chain not only with decreasing radii (forward tapering) in geometric progression, but also decorated with grains positioned on the top and bottom of the chain, without altering its original length. The decorating grains act as an auxiliary chain which traps part of the energy and linear momentum, both propagating as a pulse due to disturbances produced at the end of the chain. Thus, this configuration optimizes the impact attenuation and aligns the chain naturally (by symmetry) which facilitates the construction of the experimental setup. Furtheremore, since the decorating grain radii increase along the chain, this new type of chain is necessarily short in order to avoid precompression. Nevertheless, even with short chains, it is possible to mitigate impacts almost completely.