Shape and Mass Analysis of Fragments Generated by Natural Fragmentation Using 3D Scanning Technology
摘要
Shape and mass analysis of fragments generated from natural fragmenting projectiles has always been a significant part of the projectile design process. These fragments are of irregular shape, size, thickness and mass. The number and shape of the fragments depends largely on the material used for the projectile body (the steel is used in most cases), and energetic materials used inside the projectile body such as: TNT, RDX, HMX etc. The final shape of the fragments is irregular and stochastic, which implies that volume, surface and mass properties are subjected to a complex methodology for calculation. This paper investigates the possibility of using 3D scanner in shape and mass properties analysis of the natural fragments and its limitations. After detonation of the six steel cylinders, three heat treated and three non-heat-treated, natural fragments are collected. Five fragments are randomly chosen from each group. A total of ten fragments are scanned with Atos Core 200 (GOM, GmbH) 3D scanner, processed in Design X software, exported to a desired format and analyzed in CAD software. SolidWorks was used for fragment analysis in this case. Results of the 3D scanning show that it is possible to generate usable model of the irregularly shaped fragment. Comparison of the fragments, scanned and real fragments, does not implicate any significant difference regarding shape and mass. CAD software has proven to be useful tool for quick and easy determination of mass properties. However, it has been found that the process of 3D scanning is time consuming regarding the complexity of the fragment geometry. For the purpose of making scanning process more efficient, special tools are designed and used for fragment positioning in the scanning area of the 3D scanner with the respect to the reference points.