Fragment distribution as an aid to forensic failure investigations at the scene of explosions
- 110 Downloads
Twelve pipe bombs were exploded, and the fragments were collected and weighed. The distribution of fragment masses was shown to follow a Weibull-type form M (n)=M0 [1 − exp (−Bnλ)] when RDX-based military explosives were used and a bimodal distribution when commercial explosives were used. The constant, B, was a function of the mass of fragments recovered, making its use inappropriate in a forensic context where complete collection of the fragments would not be possible. For RDX-based explosives with added Mg or Al powder, the value of the constant, λ, was reduced compared to that of the RDX-based explosive without metal powder additions. An alternative fragment distribution formula, log [(100 M (N))/M0]=FWDM [m(N)/ M0], can also be used to distinguish between explosives, although the correlation coefficient is inevitably somewhat lower and the scatter between the results of nominally identical tests can be greater. The coefficient, FWDM, has a dependence on the mass of fragments collected, restricting its utility in forensic contexts.
Keywordsfragmentation size distribution explosives pipe bombs forensic science
Unable to display preview. Download preview PDF.
- 1.H.P. Tardif and T.S. Sterling: “Explosively Produced Fractures and Fragments in Forensic Investigations,”J. Forensic Sci., 1967,12(3), pp. 247–72.Google Scholar
- 2.R. Gurney: Report 405, Ballistics Research Laboratory, Aberdeen, MD. Quoted in M.A. Meyers,Dynamic Behavior of Materials(New York: John Wiley, 1994): pp. 229–43.Google Scholar
- 4.M. Held:Tactical Missile Warheads, J. Carleone, ed., AIAA, Washington, DC, 1993, pp. 387–464.Google Scholar
- 6.A. Roine:HSC Chemistry Version 2.03, Outukompu Research Oy, Pori, Finland.Google Scholar
- 7.Shock Waves and High-Strain-Rate Phenomena in Metals, M.A. Meyers and L.E. Murr, ed., 1981, Plenum, New York, pp. 1033–39.Google Scholar
- 8.J. Akhavan:The Chemistry of Explosives, Royal Society of Chemistry, London, 1998, pp. 69–96.Google Scholar
- 9.H. Kast:Zeitung für das gesamte Schiess- und Sprengstoffwesen-Nitrocellulose, 8, 1913, pp. 65–68. Quoted in B.T. Federoff and O.E. Sheffield, ed.,Encyclopaedia of Explosives and Related Items (Dover, NJ, Picatinny Arsenal, 1962): pp. B265–97.Google Scholar
- 10.P.W. Cooper and S.R. Kurowski:Introduction to the Technology of Explosives, Wiley VCH, New York, 1996, pp. 72–80.Google Scholar