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BAB V KESIMPULAN DAN SARAN V.1. Kesimpulan Dari hasil perhitungan dan pembahasan yang telah dilakukan, dapat diambil kesimpulan sebagai berikut : 1. Energi yang diserap pelat menunjukkan 3 buah daerah, yaitu: • Daerah I : merupakan daerah dimana proyektil belum menembus (penetrasi total) pelat. Pada daerah ini energi yang diserap pelat sama dengan energi kinetik mulamulanya. • Daerah II : merupakan daerah yang terjadi setelah balistik limit hingga kecepatan kritis. Daerah ini ditunjukkan dengan grafik naik dari setelah balistik limit hingga titik puncak pada pada grafik. • Daerah III : merupakan daerah yang terjadi setelah daerah kritis dimana daerah ini dicirikan dengan grafik turun. Pada daerah ini energi yang diserap oleh pelat menjadi kecil. 2. Lebar perforasi yang terjadi pada pelat semakin kecil seiring dengan semakin naiknya kecepatan awal proyektil. V.2. Saran Untuk kesempurnaan tugas akhir yang akan datang disarankan : 1. Model proyektil yang dipakai hendaknya diganti dengan model proyektil yang mendekati proyektil yang sebenarnya, baik dari segi ukuran, bentuk dan bahan pembentuknya 2. Algoritma penghapusan elemen yang gagal perlu diperbaiki sehingga massa yang hilang tidak berpengaruh terhadap besaran yang lain. Hal ini mungkin dapat dilakukan dengan cara mengikutsertakan efek dari hourglass. 3. Sebaiknya dalam penelitian yang lebih lanjut ukuran elemen diperkecil sehingga hasil lebih akurat.
Laporan Tugas Akhir
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DAFTAR PUSTAKA A. Brent Strong. “Polymeric Reinforcing Fibers — KEVLAR®, SPECTRA®, and others”. Brigham Young University. A. Shahkarami et al. “A Numerical Investigation of the Effect of Projectile Mass on the Energy Absorption of Fabric Panels Subjected to Ballistic Impact”. Vancouver : Dept. of Civil Engineering and Metals and Materials Engineering, The University of British Columbia. B. A. Cheeseman dan C. P. R. Hoppel. “Simulating the Ballistic Impact of Composite Structural Armor”. U.S. Army Research Laboratory. B. K. Hadi. “Mekanika Struktur Komposit”. Bandung : Penerbit ITB.2000. Kaw, Autar K, Mechanics of Composite Material, CRC Press, New York, 1997 C. T. Lim, V. P. W. Shim dan Y. H. Ng. “Finite-Element Modeling of the Ballistic Impact of Fabric Armor”. International Journal of Impact Engineering.28, 13 – 31.2003. Cantwell dan Morton. “Comparison of the Low and High Velocity Impact Response of CRFP”. Composite.20[6], 545 – 551.1989. D. Roylance. “Introduction to Composite Materials”. Cambridge : Dept. of Materials Science and Engineering, MIT.2000. F. K. Chang dan K. Y. Chang. “A Progressive Damage Model for Laminated Composites Containing Stress Concentrations”. Journal of Composite Materials. 21[8] 34 – 55.1987. G. R. Johnson, S. R. Beissel dan P. M. Cunniff. “A Computational Approach for Composite Materials Subjected to Ballistic Impact”. Singapore : Proceedings of 2nd Annual Conference on Structural Stability and Dynamics.2002.
72 G. R. Johnson, S. R. Beissel dan P. M. Cunniff. “A Computational Model for Fabrics Subjected to Ballistic Impact”. San Antonio : Proceedings of the 18th International Symposium on Ballistics.1999. H. Billon.1998.” A Model for Ballistic Impact on Soft Armour”. Combatant Protection and Nutrition Branch Aeronautical and Maritime Research Laboratory. J. A. Zukas, D.R. Scheffler. 1999. “Impact effect in multilayered plates”. International Journal of Solid and Structure 38, 3321-3328. J. O. Hallquist. 1998. “LS-DYNA Theoretical Manual”. Livermore Software Technology Corp. J. van Hoof.1999. “Modelling of impact induced delamination in composite materials”. PhD Thesis, Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Canada. J. van Hoof, D.S. Cronin., M.J. Worswick, K.V. Williams, D. Nandlall. 2001. ”Numerical Head and Composite Helmet Models to Prdict Blunt Trauma”. 19th International Symposium of Ballistics. J. W. Simons, D. C. Erlich dan D. A. Shockey. “Finite Element Design Model for Ballistic Response of Woven Fabrics”. Menlo Park : SRI International. Magnus Aare, Svein Kleiven.” Evaluation of head response to ballistic helmet impacts using the finite element method”. International Journal of Impact Engineering. Magnus Aare. 2003. “Prevention of Head Injuries Focusing Specifically on Oblique Impacts”. Doctoral Thesis, Royal Institute of Technology (KTH) Stockholm, Sweden. M. A. G. da Silva, C. Cismasiu dan C. G. Chiorean. “Ballistic Simulation of Impact on Composite Laminate”. The Universidale Nova de Lisboa.2002. M. N. G. Nejhad. “Ballistic Impact Simulations Utilizing LSDYNA3D”. Dept. of Mechanical Engineering, University of Hawaii.
73 NIJ Standard 0101.04 Rev A. : “Ballistic Resistance of Police Body Armor”. Washington : U.S. Department of Justice, National Institute of Justice.2001. Norman Jones. “Structural Impact”. Cambridge University Press.1997. Pankaj K. Porwal and S. Leigh Phoenix. 2005. “Modeling system effects in ballistic impact into multi-layered fibrous materials for soft body armor”. International Journal of Fracture 135:217–249. Paul Wambua, Marc Pirlot, Stepan Lomov and Ignaas Verpoest.“Protection Against Secondary Fragmentation From AP Mines Based on Natural Fibre Composites”. Katholieke Universiteit, Royal Military Academy P. D. Zavattieri et al. “Energy Dissipation in Ballistic Penetration of Fiber Composites”.1999. P. K. Dutta et al. “Ballistic Perforation of Graphite/Epoxy Composite”. Hannover : Special Report, 96 - 29. USACRREL.1996. P. M. Cunniff. “An Analysis of the System Effect in Woven Fabrics Under Ballistic Impact”. Textile Research Journal.62[2], 495 – 509.1992. P. M. Cunniff, J. W. Song dan J. E. Ward. “Investigation of High Performance Fibers for Ballistic Impact Resistance Potential”. Proceedings of the 21st International SAMPE Technical Conference. 22, 319 – 333.1989. R. M. Jones. “Mechanics of Composite Materials”. New York : McGraw-Hill Book Co.1975. R. S. J. Corran, P. J. Shadbolt dan C. Ruiz. “A Comparison of Plate Perforation Models in the Sub-Ordnance Impact Velocity Range”. London : International Journal of Impact Engineering.1[1], 23 – 49.1983. R. S. J. Corran, P. J. Shadbolt dan C. Ruiz. “Impact Loading of Plates - an Experimental Investigation”. London : International Journal of Impact Engineering.1[1], 3 – 22.1983.
74 Roger L. Ellis. “Ballistic Impact Resistance of Graphite Epoxy Composites with Shape Memory Alloy and Extended Chain Polyethylene Spectra TM Hybrid Components”. Blacksburg : Dept. of Mechanical Engineering, The Virginia Polytechnic Institute and State University.1996. Roylance, D., P. Chammas, J. Ting, H. Chi, and B. Scott. 1995. “Numerical Modeling Of Fabric Impact”. Procedings of the National Meeting of the American Society of Mechanical Engineers (ASME), San Francisco. S. Abrate. “Impact on Composite Structures”. Cambridge University Press. 1998. S. N. Nasser dan H. Deng. “Strain Rate Effect on Brittle Failure in Compression”. Acta Metallurgical et Materialia.42[3] 1013 – 1024.1994. S. T. Jenq, H.S. Jing and Charles Chung. 1994. “Predicting the ballistic limit for plain woven glass/epoxy composite laminate”. Int. J. Impact Engng Vol. 15, No. 4, pp. 451— 46. T. Borvik et al. “Numerical Simulation of Plugging Failure in Ballistic Penetration Using LS-DYNA”. Trondheim : Dept. of Structural Engineering, The Norwegian University of Science and Technology. W. D. Callister, Jr. “Materials Science and Engineering : An Introduction, 6th Edition”. John Wiley and Sons, Inc.2002. Young S. Lee, E.D. Wetzel, N.J. Wagner.2003.”The Ballistic Impact Characteristic of Kevlar® woven fabric impregnated with colloidal shear thickening fluid”. Journal of Material Science 38, 2825-2833. www.AZoM.com. “Metal, Ceramic, Polymer, Composite, An Engineer Resource”. AZoM.com Pty. Ltd.2003. www.cranfield.ac.uk. “Armour Materials”. Dept. of Materials and Medical Sciences, Cranfield University.2003. www.DuPont.com. “What is Kevlar ?”. Du Pont de Nemours International S. A.2003.
75 www.fevam.com. “Ballistic Protection”. FEVAM America Inc.2003. “LS-DYNA Keyword User's Manual Nonlinear Dynamic Analysis of Structures Version 950”. Livermore Software Technology Corp.1999. “LS-DYNA Keyword User's Manual Version 970”. Livermore Software Technology Corp.2003.
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HALAMAN KOSONG
