Missile Warhead Modeling: Computations and Experiments (original) (raw)

Fem Simulation Of He Blast-Fragmentation Warhead And The Calculation Of Lethal Range

2012

This paper presents the simulation of fragmentation warhead using a hydrocode, Autodyn. The goal of this research is to determine the lethal range of such a warhead. This study investigates the lethal range of warheads with and without steel balls as preformed fragments. The results from the FE simulation, i.e. initial velocities and ejected spray angles of fragments, are further processed using an analytical approach so as to determine a fragment hit density and probability of kill of a modelled warhead. In order to simulate a plenty of preformed fragments inside a warhead, the model requires expensive computation resources. Therefore, this study attempts to model the problem in an alternative approach by considering an equivalent mass of preformed fragments to the mass of warhead casing. This approach yields approximately 7% and 20% difference of fragment velocities from the analytical results for one and two layers of preformed fragments, respectively. The lethal ranges of the si...

Numerical Modeling of Rocket Warhead Detonation and Fragmentation

Numerical models provide a safer and more cost-effective method to evaluate the performance of military warheads and weapons systems. These simulations are increasingly employed for military research and development. The scientific community must be confident in the accuracy of these computations, and thus analysts need to continually validate numerical models. This paper presents results from a numerical study of the detonation and fragmentation of a rocket warhead commonly found throughout the world. ...

Real-time simulation of a fragmenting explosion for cylindrical warheads

journal of defense modeling and simulation, 2021

Explosion models based on finite element analysis (FEA) can be used to simulate how a warhead fragments. However, their execution times are extensive. Active protection systems need to make very fast predictions, before a fast attacking weapon hits the target. Fast execution times are also needed in real-time simulations where the impact of many different computer models is being assessed. Hence, FEA explosion models are not appropriate for these real-time systems. As a trade-off between accuracy and execution time, this paper creates a simulation of fragments from a warhead's explosion, using simple analytical equations. The results are verified against explosion experimental data and FEA results. The developed model then can be made available for real-time simulation and fast computation.

Comparison of Lethal Zone Characteristics of Several Natural Fragmenting Warheads

Research of HE warheads lethal zone is very complex topic because of large number of controlled and independent, sometimes correlated, influencing factors. Capability for prediction of lethal zone is based on complexity of databases regarding natural fragmentation parameters, which should contain data about warhead body material characteristics, types of explosive charge, number, mass, initial velocity and spatial distribution of fragments, battlefield terrain, distribution of soldiers on battlefield, etc. Based on experimental research (fragmentation test in Arena facilities with two types of artillery projectiles and two types of rocket warheads), analytical and numerical methods used -projectiles lethal zones are predicted and analyzed. Influence of projectile design and explosive charges on warhead lethal zone is analyzed.

Computer simulation of nuclear weapons effects

Computer simulation programs have allowed us to model and understand the results of nuclear explosives tests underground and in the atmosphere. Most current research on modeling weapons effects has concentrated in two areas; better numerical hydrodynamic techniques and better models of inelastic material behavior. New methods such as continuous rezone algorithms and free Lagrange algorithms make it possible to simulate highly distorting flows accurately and without mesh tangling associated with the traditional Lagrangian methods. The constitutive models now incorporate physical models of porous flow and fracture, replacing the more ad hoc and simple models associated with plasticity. In this paper we will briefly describe some of these new methods and illustrate them with calculations from three state-of-the-art computer programs -- SHALE, TENSOR and FLAG. The calculations include simulation of underground nuclear explosions, cratering from an atmospheric explosion, and ballistic im...

Numerical simulations for prediction of aerodynamic drag on high velocity fragments from naturally fragmenting high explosive warheads

Numerical simulation of airflow around several representative high velocity fragments, originating from naturally fragmenting HE warhead 130mm M79, was performed using FLUENT ® finite element method package. FLUENT ® software contains the broad physical modeling capabilities needed to model flow, turbulence, heat transfer for different applications, ranging from air flow over an aerodynamic surface to real combustion processes. Aerodynamic drag coefficients of fragments were predicted for a wide range of Mach numbers (0.2, 0.4, 0.6, 0.8, 1, 1.1, 1.2, 1.3, 1.5, 2, 3, 4 and 5 Ma) and for eight different positions of fragments (0°, 45°, 90°, 135°, 180°, 225°, 270°, i 315°). Different positions simulate dynamic instability of fragments during their flight through the atmosphere and account for stochastic behavior of fragments, which directly influences aerodynamic drag coefficients, fragments range and warhead lethal zones. Obtained results of aerodynamic drag coefficients were compared...

Development and Evaluation of Small Shaped Charge Jet Threats

Problems of Mechatronics Armament Aviation Safety Engineering, 2017

Because of their prolific nature on the battlefield, rocket propelled and gun-launched grenades are of particular concern to the soldier, particularly because of the severe reaction that occurs when a munition is hit by the shaped charge jet. As a result of the danger that such a detonation poses, it is necessary to more precisely understand the behaviour of munitions subjected to these types of devices. In response to these threats, standardized 81 mm and 40 mm shaped charge warheads were developed for use during threat assessment testing to act as a consistent, lower-cost representative of shaped charge projectiles commonly encountered on the battlefield, and to help quantify the interaction of these jest with explosive charges. The international standards for shaped charge jet threat testing uses the Held initiation criteria V2D, where V is the jet velocity and D is the diameter. V2D was computationally predicted using the high-rate continuum models CALE and ALE-3D. The surrogate...