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Bu çalışmada ön ve arka kısımları kompozit yüzey plakalı sandviç bir levhanın balistik özellikleri sayısal analizler ile incelenmiştir. Tasarlanan balistik koruyucu malzeme ön ve arka plakaları karbon-aramid takviyeli epoksi kompozit malzemeden, orta çekirdek ise yüksek plastik şekil değiştirme özelliği ve hafif olması nedeniyle alüminyum plakadan oluşturulmuştur. Gerçekleştirilen bu tasarımda amaç; kompozit malzemenin enerji sönümleme mekanizmalarını kullanarak ön kompozit plakada mermi enerjisinin düşürülmesi, orta alüminyum plakanın plastik deformasyon ve sürtünme kabiliyetinden yararlanma ve arka kompozit plakada ise merminin nihai enerjisinin yayılarak tamamen yok edilmesi şeklindedir. Öncelikle mermi hareketi, hesaplamalı akışkanlar analizleri (CFD) ile incelenmiştir ve plaka ön yüzüne temas öncesi mermi hızı tespit edilmiştir. Mach sayısına göre değişen direnç katsayısı değerleri incelendiğinde CFD analizleri ile elde edilen sonuçların literatürdeki çalışmalar ile uyumlu olduğu görülmüştür. Bu çalışmada, kompozit plakalar ile balistik özellikleri artırılmış hibrit sandviç levhanın balistik performansları, NIJ 0108.01 standardı test prosedürüne göre LS DYNA yazılımı ile dinamik/eksplisit analizler gerçekleştirilerek nümerik olarak incelenmiştir. Mermi olarak 9x19 mm 8 gram ağırlığındaki Parabellum FMJ fişek seçilmiş ve farklı mermi hızlarında analizler gerçekleştirilmiştir. Kompozit plaka için malzeme kartı olarak MAT 22 malzeme kartı uygulanırken, hasar modeli olarak MAT59 kartı kullanılmıştır. Merminin herhangi bir deformasyona uğramayıp malzeme üzerinde meydana getirdiği hasarı gözlemlemek amacıyla mermi çekirdeği malzemesi için MAT 20 (MAT_RIGID) malzeme modeli kullanılmış ve çelik malzeme tanımı yapılmıştır. Yapılan simülasyonlar sonucunda tasarlanan kompozit plakalı sandviç panelin NIJ II-A ve NIJ II standardına göre mermi tarafından delinemediği ve balistik koruyucu malzeme olabileceği gösterilmiştir.
In this study, the ballistic characteristics of the front and rear parts of a composite surface plate sandwich sheet were studied with numerical analyses. Designed ballistic protective material front and back plates are made of epoxy composite material supplemented with carbon-marine, while the middle core is made of aluminum plates due to its high plastic shape change and its lightness. The objective of this design is to reduce the energy of the bullet on the front composite plate using the energy disintegration mechanisms of the composite material, to take advantage of the plastic deformation and drilling capacity of the medium aluminum plate, and to completely destroy the final energy of the bullet on the back composite plate. First, the bullet movement was studied by calculated fluid analysis (CFD) and the pre-contact bullet speed was detected on the front of the plate. When the value of the resistance ratio varied according to the number of Machs was studied, the results obtained by CFD analyses were found to be compatible with the studies in literature. In this study, the ballistic performance of the hybrid sandwich sheet, enhanced the composite plates and ballistic characteristics, was numerically studied by conducting dynamic/explisit analysis with LS DYNA software according to the standard test procedure NIJ 0108.01 . Parabellum FMJ fireworks with a weight of 9x19 mm 8 grams have been selected and analyses have been carried out at different shot speeds. The MAT 22 material card is applied as a material card for the composite plate, while the MAT59 card is used as a damage model. The material model MAT 20 (MAT_RIGID) was used for the material core to observe the damage that the bullet was caused on any deformation and the steel material was defined. The results of the simulations have shown that the composite plate sandwich panel designed according to the NIJ II-A and NIJ II standards cannot be deleted by the bullet and may be a ballistic protective material.
In this study, the ballistic properties of a sandwich sheet with composite surface plate on the front and back were investigated by numerical analysis. The designed ballistic protective material front and back plates are made of carbon-aramid reinforced epoxy composite material, and the middle core is made of aluminum plate due to its high plastic deformation and lightweight. The aim of this design is to reduce the bullet energy in the front composite plate by using the energy absorption mechanisms of the composite material, to benefit from the plastic deformation and friction ability of the middle aluminum plate, and to completely destroy the final energy of the bullet in the back composite plate by spreading. First of all, the bullet motion was investigated by computational fluid analysis (CFD) and the velocity of the bullet before contact with the plate front was determined. When the resistance coefficient values varying according to the Mach number were examined, it was seen that the results obtained by CFD analysis were compatible with the studies in the literature. In this study, the ballistic performance of hybrid sandwich plate with enhanced ballistic properties with composite plates was investigated numerically by performing dynamic/explicit analyzes with LS DYNA software according to NIJ 0108.01 standard test procedure. Parabellum FMJ cartridge, 9x19 mm and 8 grams in weight, was chosen as the bullet, and analyzes were carried out at different bullet velocities. While MAT 22 material card was applied as material card for composite plate, MAT59 card was used as damage model. In order to observe the damage caused by the bullet without any deformation on the material, the MAT 20 (MAT_RIGID) material model was used for the bullet material and a steel material definition was made. As a result of the simulations, it has been shown that the designed composite plate sandwich panel cannot be perforated by the bullet according to the NIJ II-A and NIJ II standards and can be a ballistic protective material.
Alan : Fen Bilimleri ve Matematik; Mühendislik
Dergi Türü : Uluslararası
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