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 | Ballistic Performance of Coconut Shell Powder/Twaron Fabric against Non-armour Piercing Projectiles
Author : Risby, M. S.; Wong, S. V.;Hamouda, A. M. S.;Khairul, A. R.;Elsadig, M.
Source : Defence Science Journal ; Vol:58(2) ; 2008 ; pp 248-263
Subject :
Keywords : Coconut shell powder;Ballistic impact;Armour panel;Natural composite material;Composite armour;Twaron fabric
Abstract : Body armour technologists over the years are seeking to develop protective systems which are both effective and lightweight. However these hard armour materials are very expensive and have certain weight constraints. From this point of view, natural fibres and fillers have attracted the attention of researchers due to their low density with high specific strengths, abundance, availability, renewability and being environmental-friendly. This paper reports the potential use of coconut shell powder-epoxy composite (COEX) panel bonded with Twaron CT716 fabric as a hard armour material and the characteristics of its fracture imprints from a specific threat level when subjected to ballistic tests1 (NIJ Standard 0108.01). It was observed that the imprint patterns on the particulate composite (COEX) could be identified according to effectiveness in impact energy dissipation. COEX/Twaron test panel was found to withstand impact equivalent to NIJ Level IIIA using 9 mm FMJ ammunition but perforated at NIJ Level III of 7.62 mm FMJ bullet impacts. Test results showed that COEX panel do possess shock absorbance characteristics and can be utilised as an armour component in the hard-body armour system. Dependency on Twaron fabric layers as ballistic reinforcements has been reduced up to 3-time with 170 per cent improvement on energy-absorption capabilities when using COEX composite as the frontal component of the armour. |
| | Influence of Polymer Restraint on Ballistic Performance of Alumina Ceramic Tiles
Author : Reddy, P. R. S.;Madhu, V.;Ramanjaneyulu, K.;Balakrishna Bhat, T.;Jayaraman, K.;Gupta, N. K.
Source : Defence Science Journal ; Vol:58(2) ; 2008 ; pp 264-274
Subject :
Keywords : Alumina ceramic;Ballistic impact;Polymer fibres;Confinement;Projectile
Abstract : Influence of Polymer Restraint on Ballistic Performance of Alumina Ceramic Tiles |
| | Numerical Simulation of Projectile Impact on Mild Steel Armour Plates using LS-DYNA: Part I: Validation
Author : Deb, A.;Raguraman, M.;Gupta, N. K.;Madhu, V.
Source : Defence Science Journal ; Vol:58(3) ; 2008 ; pp 422-432
Subject : 669 Metallurgy;66 Chemical Technology
Keywords : Projectile;Mild steel plate;Ballistic impact;Simulation;LS-DYNA
Abstract : The paper describes the simulation of impact of jacketed projectiles on steel armour plates using explicit finite element analysis as implemented in LS-DYNA. Validation of numerical modelling includes a comprehensive mesh convergence study leading to insights not previously reported in literature, using shell, solid, and axisymmetric elements for representing target plates. It is shown for a number of cases that with a proper choice of contact algorithm, element size, and strain rate-dependent material properties, computed projectile residual velocities can match closely with corresponding test-based values. The modelling requirements are arrived at by correlating against published test residual velocities1 for variants of mild steel plates (designated as MS1, MS2 and MS3) of different thicknesses at impact velocities in the range of ~820-870 m/s. Using the validated numerical procedure, a number of parametric studies such as the effect of projectile shape and geometric aspect ratios as well as plate thickness on residual velocity have been carried out and presented in Part II of the current paper. |
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