Das R, Collins A, Verma A, Fernandez J, Taylor M. Evaluating simulant materials for understanding cranial backspatter from a ballistic projectile.
J Forensic Sci 2015;
60:627-37. [PMID:
25739515 DOI:
10.1111/1556-4029.12701]
[Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 04/03/2014] [Accepted: 04/17/2014] [Indexed: 11/29/2022]
Abstract
In cranial wounds resulting from a gunshot, the study of backspatter patterns can provide information about the actual incidents by linking material to surrounding objects. This study investigates the physics of backspatter from a high-speed projectile impact and evaluates a range of simulant materials using impact tests. Next, we evaluate a mesh-free method called smoothed particle hydrodynamics (SPH) to model the splashing mechanism during backspatter. The study has shown that a projectile impact causes fragmentation at the impact site, while transferring momentum to fragmented particles. The particles travel along the path of least resistance, leading to partial material movement in the reverse direction of the projectile motion causing backspatter. Medium-density fiberboard is a better simulant for a human skull than polycarbonate, and lorica leather is a better simulant for a human skin than natural rubber. SPH is an effective numerical method for modeling the high-speed impact fracture and fragmentations.
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