• 대한기계학회논문집A
• /
• 제41권1호
• /
• pp.1-6
• /
• 2017

헬멧을 착용한 병사의 비관통 피탄 충격은 총탄이 헬멧을 관통하지 않더라도 인체에 치명적인 상해를 유발한다. 이로 인한 인체 상해 해석을 위한 연구들이 이뤄져 왔으나 주로 두부의 손상에 초점을 맞춘 해석 모델이 개발되어 왔다. 비관통 피탄 충격에 의한 경추 및 경추부 관련 근육의 손상은 인체에 치명적인 상해를 입히지 않더라도 병사의 생존성에 상당한 영향을 미친다. 따라서 경추 및 경추부 근육을 포함한 모델 개발이 필요하다. 본 연구에서는 기존에 연구된 두부 모델과 근육 모델이 적용된 경추부 모델을 활용하여 인체의 상해해석을 수행하였다. 정량적 상해예측을 위해 응력, 변형률 및 HIC를 비교하였다. 경추부가 포함된 모델의 해석결과는 두부 모델만 고려된 해석결과보다 상해 정도를 작게 예측하였다. 모델의 신뢰성 확보를 위하여 두부 상해 해석 결과를 타 문헌과 비교하였다.

• 대한기계학회논문집A
• /
• 제40권2호
• /
• pp.229-236
• /
• 2016

본 연구에서는 자주박격포의 다물체동역학 모델을 만든 뒤, 포탄의 탄도학을 고려하여 시뮬레이션 하였다. 자주박격포 모델은 박격포 모델 및 차량 모델로 구성하였으며, 상용 다물체 해석 프로그램인 RecurDyn 을 사용하였다. 차량 모델은 6 자유도 강체플랫폼으로 모델링 하였으며, 박격포 발사 직후의 움직임에는 강내탄도학을 적용하였다. 강내탄도학 해석의 결과를 바탕으로, 포신을 떠난 후의 강외탄도 해석을 수행하였다. 몬테카를로 기법을 활용한 반복 해석으로 발사각과 차량 동특성에 의한 변동이 고려된 탄착점의 분산도를 구하여 사격정확도를 제시하였다.

• Journal of electromagnetic engineering and science
• /
• 제18권4호
• /
• pp.231-241
• /
• 2018

In this paper, we consider the anti-attack procedure of a ballistic missile defense system (BMDS) at different operating frequencies at its phased-array radar station. The interception performance is measured in terms of lateral divert (LD), which denotes the minimum acceleration amount available in an interceptor to compensate for prediction error for a successful intercept. Dependence of the frequency on estimation accuracy that leads directly to prediction error is taken into account, in terms of angular measurement noises. The estimation extraction is performed by means of an extended Kalman filter (EKF), considering two typical re-entry trajectories of a non-maneuvering ballistic missile (BM). The simulation results show better performance at higher frequency for both tracking and intercepting aspects.

• 한국군사과학기술학회지
• /
• 제10권2호
• /
• pp.31-37
• /
• 2007

This paper presents a ballistic lead-computation method which utilizes automatic video tracking, tracking assistance and roll uncoupling. The method is able to improve the firing accuracy of army fighting vehicles such as main battle tanks. In the experiment, the efficiency of the proposed method is evaluated by an error analysis in real operating environment. The proposed method has been applied to the fire control system of a military vehicle and proved through the development test of the vehicle.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.1376-1381
• /
• 2004

Understanding the thermal conductivity and heat transfer processes in superlattice structures is critical for the development of thermoelectric materials and optoelectronic devices based on quantum structures. $Chen^{(1)}$ developed ballistic diffusive equation(BDE) for alternatives of the Boltzmann equation that can be applied to the complex geometrical situation. In this study, a simulation code based on BDE is developed and applied to the 1-dimensional transient heat conduction across a thin film and transient 2-dimensional heat conduction across the film with heater. The obtained results are compared to the results of the $Chen^{(1)}$ and Yang and $Chen^{(1)}$. Finally, steady 2-dimensional heat conduction in the quantum dot superlattice are solved to obtain the equivalent thermal conductivity of the lattice and also compared with the experimental data from $Borca-Tasciuc^{(2)}$.

• 한국멀티미디어학회논문지
• /
• 제22권7호
• /
• pp.815-821
• /
• 2019

This paper presents the design and implementation of a Mission Planning System(MPS) for multiple ballistic missiles. MPSs are also a kind of M&S systems in defense domain, and these provide important computations on the ground before flights of flying objects. The proposed MPS in this paper has a new concept which is far from generating a set of waypoints of a flying object and proving the set. In this paper, we firstly discuss the research motivation of our own MPS; then, we introduce the design of our MPS and its functionalities. In order to prove the practicality of our MPS, we have conducted a case study.

• Advances in nano research
• /
• 제12권5호
• /
• pp.529-547
• /
• 2022

Graphene is one of the strongest, stiffest, and lightest nanoscale materials known to date, making it a potentially viable and attractive candidate for developing lightweight structural composites to prevent high-velocity ballistic impact, as commonly encountered in defense and space sectors. In-plane twist in bilayer graphene has recently revealed unprecedented electronic properties like superconductivity, which has now started attracting the attention for other multi-physical properties of such twisted structures. For example, the latest studies show that twisting can enhance the strength and stiffness of graphene by many folds, which in turn creates a strong rationale for their prospective exploitation in high-velocity impact. The present article investigates the ballistic performance of twisted bilayer graphene (tBLG) nanostructures. We have employed molecular dynamics (MD) simulations, augmented further by coupling gaussian process-based machine learning, for the nanoscale characterization of various tBLG structures with varying relative rotation angle (RRA). Spherical diamond impactors (with a diameter of 25Å) are enforced with high initial velocity (V_i) in the range of 1 km/s to 6.5 km/s to observe the ballistic performance of tBLG nanostructures. The specific penetration energy (E_p^*) of the impacted nanostructures and residual velocity (V_r) of the impactor are considered as the quantities of interest, wherein the effect of stochastic system parameters is computationally captured based on an efficient Gaussian process regression (GPR) based Monte Carlo simulation approach. A data-driven sensitivity analysis is carried out to quantify the relative importance of different critical system parameters. As an integral part of this study, we have deterministically investigated the resonant behaviour of graphene nanostructures, wherein the high-velocity impact is used as the initial actuation mechanism. The comprehensive dynamic investigation of bilayer graphene under the ballistic impact, as presented in this paper including the effect of twisting and random disorder for their prospective exploitation, would lead to the development of improved impact-resistant lightweight materials.

• Advances in Computational Design
• /
• 제1권2호
• /
• pp.139-154
• /
• 2016

The usage of sandwich structure is extensively increasing in lightweight protective structures due to its low density and other useful properties. Sandwich panels made of metal sheets with unfilled cellular cores are found to exhibit lower deflections by comparing to an equivalent monolithic plate of same metal and similar mass per unit density. However, the process of localized impact on solid structures involving plastic deformation, high strain rates, temperature effect, material erosion, etc. does not hold effectively as that of monolithic plate. In present work, the applications of the sandwich plate with corrugated core have been extended to develop optimized lightweight armour using foam as medium of its core by explicit finite element analysis (FEA). The mechanisms of hardened steel projectile penetration of aluminum corrugated sandwich panels filled with foams have been numerically investigated by finite element analysis (FEA). A comparative study is done for the triangular corrugated sandwich plate filled with polymeric foam and metallic foam with different densities in order to achieve the optimum penetration resistance to ballistic impact. Corrugated sandwich plates filled with metallic foams are found to be superior when compared to the polymeric one. The optimized results are then compared with that of equivalent solid and unfilled cores structure to observe the effectiveness of foam-filled corrugated sandwich plate which provides an effective resistance to ballistic response. The novel structure can be the alternative to solid aluminum plate in the applications of light weight protection system.

• Computers and Concrete
• /
• 제27권1호
• /
• pp.1-12
• /
• 2021

This work presents a safety assessment of an underground tunnel subjected to a ballistic missile attack employing the numerical approach. For the impact simulation, a box shaped reinforced concrete (RC) structure with a cross section dimension of 8.0×10.0 m under a soil layer that was attacked by a SCUD missile was modeled using finite element (FE) software LS-DYNA. SCUD missile is one of a series of tactical ballistic missiles developed by Soviet Union during the Cold War, which is adopted for a short-range ballistic missile. The developed FE simulation for the penetration depth of the missile impacting into the soil structure was verified from the well-known formula of the penetration prediction. The soil-structure interaction, the soil type, and the impact missile velocity effects on the penetration depth of the missile into the different soil types were investigated. The safety assessment of the underground tunnel was performed with regard to the different depths of the underground tunnel. For each missile velocity and soil type, a specific depth called the unsafe depth was obtained from the analysis results. The structure beneath the soil beyond this depth remains safe. The unsafe depth was found to be increased with the increasing missile velocity.

• 산업경영시스템학회지
• /
• 제44권4호
• /
• pp.43-52
• /
• 2021

In weapon assignment studies to defend against threats such as ballistic missiles and long range artillery, threat assessment was partially lacking in analysis of various threat attributes, and considering the threat characteristics of warheads, which are difficult to judge in the early flight stages, it is very important to apply more reliable optimal solutions than approximate solution using LP model, Meta heuristics Genetic Algorithm, Tabu search and Particle swarm optimization etc. Our studies suggest Generic Rule based threat evaluation and weapon assignment algorithm in the basis of various attributes of threats. First job of studies analyzes information on Various attributes such as the type of target, Flight trajectory and flight time, range and intercept altitude of the intercept system, etc. Second job of studies propose Rule based threat evaluation and weapon assignment algorithm were applied to obtain a more reliable solution by reflection the importance of the interception system. It analyzes ballistic missiles and long-range artillery was assigned to multiple intercept system by real time threat assessment reflecting various threat information. The results of this study are provided reliable solution for Weapon Assignment problem as well as considered to be applicable to establishing a missile and long range artillery defense system.