Effect of change of sand properties on travel distance of ricocheted debris

Yoon Keon Kim, Woo Chun Choi

Research output: Contribution to journalArticle

Abstract

The debris from exploded buildings can ricochet after colliding with the ground, thus increasing the debris travel distance and danger from any associated impacts or collisions. To reduce this danger, the travel distance of ricocheted debris must be accurately predicted. This study analyzed the change in the travel distance of ricocheted concrete debris relative to changes in the properties of a sand medium. Direct shear tests were conducted to measure the change in internal friction angle as a function of temperature and water content of the sand. Finite element analysis (FEA) was then applied to these variables to predict the speed and angle of the debris after ricochet. The FEA results were compared with results of low-speed ricochet experiments, which employed variable temperature and water content. The travel distance of the debris was calculated using MATLAB, via trajectory equations considering the drag coefficient. As the internal friction angle decreased, the shear stress decreased, leading to deeper penetration of the debris into the sand. As the loss of kinetic energy increased, the velocity and travel distance of the ricocheted debris decreased. Changes in the ricochet velocity and travel distance of the debris, according to changes in the internal friction angle, indicated that the debris was affected by the environment.

Original languageEnglish
JournalDefence Technology
DOIs
Publication statusAccepted/In press - 2020

Keywords

  • Environmental change
  • Exploded debirs
  • Internal friction angle
  • Ricochet
  • Sand
  • Temperature
  • Travel distance
  • Water content

ASJC Scopus subject areas

  • Computational Mechanics
  • Ceramics and Composites
  • Mechanical Engineering
  • Metals and Alloys

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