• Title/Summary/Keyword: static perforation

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Prediction of Ballistic Limit for Composite Laminates Subjected to High-velocity Impact Using Static Perforation Test (정적압입 관통 실험을 이용한 복합재 적층판의 고속충격 탄도한계속도 예측)

  • You, Won-Young;Kim, In-Gul;Lee, Seokje;Kim, Jong-Heon
    • Composites Research
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    • v.26 no.1
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    • pp.21-28
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    • 2013
  • The ballistic limit of Carbon/Epoxy composite laminates with the finite effective area are predicted by using the quasi-static perforation test and semi-empirical formula. The perforation energy were calculated from force-displacement curve in quasi-static perforation test. Also, the actual ballistic limit and penetration energy were obtained through the high-velocity impact test. The quasi-static perforation test and high-velocity impact test were conducted for the specimens with 3 different effective areas. In the high-velocity impact test, the air gun impact tester were used, and the ballistic and residual velocity was measured. The required inputs for the semi-empirical formula were determined by the quasi-static perforation tests and high-velocity impact tests. The comparison between semi-empirical formula and high-velocity impact test results were conducted and examined. The ballistic limits predicted by semi-empirical formula were agreed well with high-velocity impact test results.

Prediction of the Penetration Energy for Composite Laminates Subjected to High-velocity Impact Using the Static Perforation Test (정적압입 관통실험을 이용한 복합재 적층판의 고속충격 관통에너지 예측)

  • You, Won-Young;Lee, Seokje;Kim, In-Gul;Kim, Jong-Heon
    • Composites Research
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    • v.25 no.5
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    • pp.147-153
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    • 2012
  • In this paper, static perforation tests are conducted to predict the penetration energy for the composite laminates subjected to high velocity impact. Three methods are used to analyze the perforation energy accurately. The first method is to select the perforation point using the AE sensor signal energy, the second method is to retest the tested specimen and use the difference between initial and retested perforation energy, and the third method is to select the perforation point based on the maximum loading point in the retested load-displacement curve of the tested specimen. The predicted perforation energy results are presented and verified by comparing with those by the high velocity tests.

Laminate composites behavior under quasi-static and high velocity perforation

  • Yeganeh, E. Mehrabani;Liaghat, G.H.;Pol, M.H.
    • Steel and Composite Structures
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    • v.22 no.4
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    • pp.777-796
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    • 2016
  • In this paper, the behavior of woven E-glass fabric composite laminate was experimentally investigated under quasi-static indentation and high velocity impact by flat-ended, hemispherical, conical (cone angle of $37^{\circ}$ and $90^{\circ}$) and ogival (CRH of 1.5 and 2.5) cylindrical perforators. Moreover, the results are compared in order to explore the possibility of extending quasi-static indentation test results to high velocity impact test results in different characteristics such as perforation mechanisms, performance of perforators, energy absorption, friction force, etc. The effects of perforator nose shape, nose length and nose-shank connection shapes were investigated. The results showed that the quasi-static indentation test has a great ability to predict the high velocity impact behavior of the composite laminates especially in several characteristics such as perforation mechanisms, perforator performance. In both experiments, the highest performance occurs for 2.5 CRH projectile and the lowest is related to blunt projectiles. The results show that sharp perforators indicate lower values of dynamic enhancement factor and the flat-ended perforator represents the maximum dynamic enhancement factor among other perforators. Moreover, damage propagation far more occurred in high velocity impact tests then quasi-static tests. The highest damage area is mostly observed in ballistic limit of each projectile which projectile deviation strongly increases this area.

The high-rate brittle microplane concrete model: Part II: application to projectile perforation of concrete slabs

  • Frank, Andreas O.;Adley, Mark D.;Danielson, Kent T.;McDevitt, Henry S. Jr.
    • Computers and Concrete
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    • v.9 no.4
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    • pp.311-325
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    • 2012
  • In this paper, we examine the behavior of the High-Rate Brittle Microplane (HRBM) concrete model based on a series of penetration experiments. These experiments were conducted with three different slab thicknesses (127, 216 and 254 mm) that provided a significant challenge for the numerical simulations. The 127 mm slab provided little resistance, the 216 mm slab provided nominal resistance and the 254 mm slab approached the perforation limit thickness of the projectile. These experiments provide a good baseline for evaluating material models since they have been shown to be extremely challenging; in fact, we have not encountered many material models that can provide quantitatively predictive results in terms of both projectile exit velocity and material damage. In a companion paper, we described the HRBM material model and its fit to various quasi-static material property data for WES-5000 concrete. In this paper, we show that, when adequately fit to these quasi-static data, the HRBM model does not have significant predictive capabilities, even though the quasi-static material fit may be exceptional. This was attributed to the rate-dependent response of the material. After various rate effects were introduced into the HRBM model, the quantitative predictive nature of the calculations dramatically increased. Unfortunately, not much rate-dependent material property data are in the literature; hence, accurate incorporation of rate effects into material models is difficult. Nonetheless, it seems that rate effects may be critical in obtaining an accurate response for concrete during projectile perforation events.

The Experimental Study on the Absorbed Energy of Carbon/Epoxy Composite Laminated Panel Subjected to High-velocity Impact (고속 충격을 받는 Carbon/Epoxy 복합재 적층판의 흡수 에너지 예측에 대한 실험적 고찰)

  • Cho, Hyun-Jun;Kim, In-Gul;Lee, Seokje;Woo, Kyeongsik;Kim, Jong-Heon
    • Composites Research
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    • v.26 no.3
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    • pp.175-181
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    • 2013
  • The evaluation and prediction for the absorbed energy, residual velocity, and impact damage are the key things to characterize the impact behavior of composite laminated panel subjected to high-velocity impact. In this paper, the method to predict the residual velocity and the absorbed energy of Carbon/Epoxy laminated panel subjected to high velocity impact are proposed and examined by using quasi-static perforation test and high-velocity impact test. Total absorbed energy of specimen due to the high-velocity impact can be grouped with static energy and kinetic energy. The static energy are consisted of energy due to the failure of the fiber and matrix and static elastic energy, which are related to the quasi-static perforation energy. The kinetic energy are consisted of kinetic energy of moving part of specimen, which are modelled by three modified kinetic model. The high-velocity impact test were conducted by using air gun impact facility and compared with the predicted values. The damage area of specimen were examined by C-scan image. In the high initial impact velocity above the ballistic limit, both the static energy and the kinetic energy are known to be the major contribution of the total absorbed energy.

Polypropylene fiber reinforced concrete plates under fluid impact. Part I: experiments

  • Korucu, Hasan
    • Structural Engineering and Mechanics
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    • v.60 no.2
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    • pp.211-223
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    • 2016
  • Static loading and fluid impact tests on plates containing mesh reinforcement and polypropylene fibers in ratios of 0 to 3% by volume were performed. The objective was to observe the effect of fluid mass on the total impulse that caused the impact event and the influence of fiber amount on the impact resistance, and to estimate the velocity of fluid that causes scabbing, perforation or total disintegration. The study is the first to express the fluid impact resistance of polypropylene fiber reinforced concrete plates.

Effect of rebar spacing on the behavior of concrete slabs under projectile impact

  • Abbas, Husain;Siddiqui, Nadeem A.;Almusallam, Tarek H.;Abadel, Aref A.;Elsanadedy, Hussein;Al-Salloum, Yousef A.
    • Structural Engineering and Mechanics
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    • v.77 no.3
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    • pp.329-342
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    • 2021
  • In this paper, the effect of different steel bar configurations on the quasi-static punching and impact response of concrete slabs was studied. A total of forty RC square slab specimens were cast in two groups of concrete strengths of 40 and 63 MPa. In each group of twenty specimens, ten specimens were reinforced at the back face (singly reinforced), and the remaining specimens were reinforced on both faces of the slab (doubly reinforced). Two rebar spacing of 25 and 100 mm, with constant reinforcement ratio and effective depth, were used in both singly and doubly reinforced slab specimens. The specimens were tested against the normal impact of cylindrical projectiles of hemispherical nose shape. Slabs were also quasi-statically tested in punching using the same projectile, which was employed for the impact testing. The experimental response illustrates that 25 mm spaced rebars are effective in (i) decreasing the local damage and overall penetration depth, (ii) increasing the absorption of impact energy, and (iii) enhancing the ballistic limit of RC slabs. The ballistic limit was predicted using the quasi-static punching test results of slab specimens showing a strong correlation between the dynamic perforation energy and the energy required for quasi-static perforation of slabs.

Penetration mechanisms of non-deforming projectiles into reinforced concrete barriers

  • Dancygier, Avraham N.;Yankelevsky, David Z.
    • Structural Engineering and Mechanics
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    • v.13 no.2
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    • pp.171-186
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    • 2002
  • Static and dynamic penetration tests of reinforced concrete (RC) slab specimens are described and discussed. The experimental study was aimed at a better understanding of mechanisms that are involved in dynamic penetration, through their identification in static tests, and by establishing their relative influence in similar dynamic cases. The RC specimens were $80{\times}80-cm$ square plates, and they were made of 30 MPa concrete. The non-deforming steel penetrator was a 50-mm diameter steel rod with a conical nose of 1.5 aspect ratio. Impact penetration tests were carried out with an air gun, which launched the projectiles at velocities of up to 300 m/sec. The static tests were conducted using a closed loop displacement control actuator, where the penetrator was pushed at a constant rate of displacement into the specimen. The static tests reveal important mechanisms that govern the penetration process and therefore contribute to a better understanding of RC barriers resistance to non-deforming projectiles impact.

A Study on the Deformation and Perforation Problem for Steel Plates Subjected to High-Speed Collision and Superhigh-Speed Collision (고속충돌 및 초고속충돌 강판구조물의 대변형 관통문제에 관한 연구)

  • 원석희;이경언;고재용;이계희;이제명;백점기;이성로
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.95-99
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    • 2004
  • This paper describe inner-collision-characteristics of the ship structural plates when the projectile collides with plate-material using LS-DYNA3D which is general and useful finite element analysis tool in collision problem fields. The series analyses were carried out from high speed(41.56m/s-118.9m/s) to ultrahigh speed(544.05m/s-800m/s). Through these analyses we can approach empirical formula to estimate penetration limit of the ship structural plates with which the projectile of various speed collides.

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Credibility Evaluation of Versatile Weight Lightening Plywood Using Piercing (천공공법을 이용한 다목적 경량 합판의 신뢰성 평가)

  • Kim, Jin-Woo;Kim, Hye-Soo;Kim, Chang-Uk;Song, Jung-Il
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.55-60
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    • 2013
  • In this study, mechanical properties of versatile light weight plywood(manufacturing using piercing) are studied. A credibility evaluation was carried out for different perforation patterns including octagonal shape, rectangular shape and circular shape. A static structural analysis is conducted to find the stresses produced. Circular perforations are found to have better strength to weight ratio. Results of each type of perforation are discusses and compared.