Low-resistive vibratory penetration in granular media

PLoS One. 2017 Apr 18;12(4):e0175412. doi: 10.1371/journal.pone.0175412. eCollection 2017.

Abstract

Non-cohesive materials such as sand, dry snow or cereals are encountered in various common circumstances, from everyday situations to industry. The process of digging into these materials remains a challenge to most animals and machines. Within the animal kingdom, different strategies are employed to overcome this issue, including excavation methods used by ants, the two-anchor strategy employed by soft burrowers such as razor-clams, and undulatory motions exhibited by sandfish lizards. Despite the development of technology to mimic these techniques in diggers and robots, the limitations of animals and machines may differ, and mimicry of natural processes is not necessarily the most efficient technological strategy. This study presents evidence that the resisting force for the penetration of an intruder into a dry granular media can be reduced by one order of magnitude with small amplitude (A ≃ 10 μm) and low frequency (f = 50 - 200 Hz) mechanical vibrations. This observed result is attributed to the local fluidization of the granular bed which induces the rupture of force chains. The drop in resistive force on entering dry granular materials may be relevant in technological development in order to increase the efficiency of diggers and robots.

MeSH terms

  • Animals
  • Biomechanical Phenomena*
  • Bivalvia / physiology
  • Computer Simulation*
  • Friction / physiology*
  • Lizards / physiology
  • Locomotion / physiology
  • Models, Theoretical*
  • Motion
  • Particle Size
  • Silicon Dioxide / chemistry
  • Soil / chemistry
  • Stress, Mechanical
  • Vibration

Substances

  • Soil
  • Silicon Dioxide

Grants and funding

The research was funded by El Fondo Nacional de Desarrollo Científico y Tecnológico by the way of the Fondecyt No. 3160167 and the Anillo ACT-1412. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.