Armored Fighting Vehicles Research Articles

A Theoretical Approach in the Design of Single Frame 28 V DC and 270 V DC Dual Voltage Generator

Armored Fighting Vehicles (AFVs) generally operate with a 28 V DC electrical system. However, the demand for electrical power in AFVs has exceeded the capabilities of the existing 28V system. The additional load growth necessitates larger wire sizes, which adds extra weight and cost to the vehicle. Introducing a dual-bus architecture (28 V DC and 270 V DC) can lead to the efficient operation of the electrical system while meeting future demand. This paper presents the design of a Brushless Direct Current (BLDC) Dual Voltage Generator (DVG), which simultaneously outputs two voltages (28 V DC & 270 V DC) from a single frame across a wide operational speed range. The design process includes a detailed description of the individual stages, accompanied by analytical parameters and software-generated results. The modeling and analysis of the generator were carried out using Motorsolve design software. The obtained results are presented and thoroughly discussed in this paper.

Influence of Welding Consumables on Ballistic Performance of Gas Metal Arc Welded Ultra-high Hard Armor Steel Joints

Steels with high strength and high hardness are considered to be the essential criteria for weight reduction in armored fighting vehicles (AFVs). Ultrahigh hard armor (UHA) steels are higher hardness (>500 HV) and higher strength (>1,500 MPa) than the currently used rolled homogenous armor (RHA) steels. The occurrence of both a tempered region in the grain-refined heat-affected zone (HAZ) and hydrogen-induced cracking (HIC) has become the limiting factor in the life extension of weld in high-strength and high-hardness armor grade steels. Hence, an attempt was made to weld UHA steel by gas metal arc welding (GMAW) process using different three filler metals (1) austenitic stainless steel (ASS), (2) duplex stainless steel (DSS), and (3) low-hydrogen ferritic. The ballistic performance of the joints was evaluated based on the area density and depth of penetration. The mechanical properties (transverse tensile, hardness, and impact toughness) and microstructural features of welded joints are correlated with the ballistic performance. All the joints stopped the 7.62 × 51 ball projectile at the weld metal region. However, through-hole (perforation) was observed when tested against the 7.62 × 54 armor piercing projectile. The joints fabricated using ASS filler wire showed superior ballistic resistance, a lesser degree of HAZ softening, and better impact toughness properties due to the higher energy absorption capability of the austenitic phase.

Effect of inner liner material on penetration behavior of reactive material double-layered liner shaped charge

To improve the insufficient penetration depth of the traditional single reactive liner shaped charge, the penetration enhancement behaviors of a reactive material double-layered liner (RM-DLL) shaped charge are investigated. This RM-DLL consists of an inner liner with metal materials and an outer liner with (polytetrafluoroethylene) PTFE/Al reactive materials. Based on the platform of AUTODYN-2D code, the influence of inner liner material on the jet formation of RM-DLL shaped charge and its penetration performance of multi-layered space plates were conducted. The numerical results indicated that, during the jet formation stage, the inner metal liner mainly formed a high-velocity precursor jet and the outer reactive liner became a major part of the slug. With increasing the material density of inner liner, the jet tip velocity and tip diamater decreased, and the effective mass of precursor jet also dropped off. For a given penetration time, with the increase in the material density of inner liner, the penetration capability of the RM-DLL shaped charge increased, whereas the mass of reactive materials entering the penetrated steel target decreased significantly. This RM-DLL shaped charge, incorporating the penetration capability of a precursor metal jet and the deflagration effects of the follow-thru reactive materials, will produce extremely damage to the desired target, typically such as the armored fighting vehicles.

Application of PTFE/Al Reactive Materials for Double-Layered Liner Shaped Charge.

The penetration enhancement behaviors of a reactive material double-layered liner (RM-DLL) shaped charge against thick steel targets are investigated. The RM-DLL comprises an inner copper liner, coupled with an outer PTFE (polytetrafluoroethylene)/Al reactive material liner, fabricated via a cold pressing/sintering process. This RM-DLL shaped charge presents a novel defeat mechanism that incorporates the penetration capability of a precursor copper jet and the chemical energy release of a follow-thru reactive material penetrator. Experimental results showed that, compared with the single reactive liner shaped charge jet, a deeper penetration depth was produced by the reactive material-copper jet, whereas the penetration performance and reactive material mass entering the penetrated target strongly depended on the reactive liner thickness and standoff. To further illustrate the penetration enhancement mechanism, numerical simulations based on AUTODYN-2D code were conducted. Numerical results indicated that, with increasing reactive liner thickness, the initiation delay time of the reactive materials increased significantly, which caused the penetration depth and the follow-thru reactive material mass to increase for a given standoff. This new RM-DLL shaped charge configuration provides an extremely efficient method to enhance the penetration damage to various potential targets, such as armored fighting vehicles, naval vessels, and concrete targets.

Touch-and-Go: Interior Tactile Communication in Armored Fighting Vehicles

In armored fighting vehicles (AFVs), the vehicle commander (VC) and crew communicate through an audio system that all crew members inside the AFV can hear. This can be distracting and inconvenient, especially for effective communication between the VC and the driver. We assessed the feasibility and usability of a tactile system for direct communication between the VC and the driver in addition to (or instead of) the existing auditory system. Field experiment results show that, with or without auditory commands, tactile cues can be utilized to direct AFV drivers during operational tasks. Hence, specific design and implementation of a tactile interface should be considered for internal communication traffic.

Effect of injection pressure on engine parameters of a high power density heavy duty diesel engine for armored fighting vehicles

This paper presents the results of a parametric study on the effect of varying the fuel injection pressure of a turbocharged multi-cylinder heavy duty off-highway diesel engine. The study is based on one-dimension engine models simulated in AVL BOOST™ engine simulation software. The base engine model has been validated using performance data from test bench. The fuel injection pressure has been varied and the start of injection has been swept at each injection pressure and speed. As a result, a collection of data has been obtained from which the injection pressure and the start of injection for the most efficient engine performance would be obtained as a function of speed. The generated data could serve as an input for detailed CFD simulations for further optimisation.

Projectile Penetrating Multilayer Composite Armor

Objectives: The objective of this paper is to study the influence of interface between multi layered composite structures in penetration problems, using finite element solver RADIOSS. Methods/Statistical Analysis: Finite element modeling of the penetrating projectile, multilayer composite and analysis using RADIOSS is done. The analysis is confined to Johnson Cook material model for plasticity and failure. One of the important aspects of material model is the representation of the plasticity and failure region. The modified interface creates a realistic environment with combination of TYPE 2 and TYPE 7 influences multiple hit of projectiles and does not influence the depth of penetration when compared to the TYPE 7 interface. Findings: Hyper Works software tool is used to simulate the projectile penetrating armor plate and Hyper Mesh used for preprocessing and RADIOSS as a solver. The depth of penetration is not significantly affected due to the TYPE 2 interface. However, the delamination behavior of the layers is captured in the TYPE 2 interface when compared to TYPE7. The modified interface with combination of TYPE 2 and TYPE 7 does not influence the depth of penetration when compared to the TYPE 7 interface. TYPE 7 formulations gives considerably acceptable results for capturing the depth of penetration in case of multilayer composite structures. TYPE 2 interfaces has to be studied in cases where delamination has influence, for example in multiple hits of projectiles etc. Application/Improvements: Development of alternative material or sandwich structure is required for the future war scenario to prevent the main threats for Armored Fighting Vehicles (AFVs), shock and penetration as future war scenario insists on light tanks that can withstand penetration with higher order of destruction.

The Redeployment of Chechnya-Based Troops to Dagestan: Background, Motives, and Repercussions

IntroductionChechnya and Dagestan are two key autonomous republics in the North Caucasus. These two republics have the largest populations among the autonomous republics in the region, and have a strong tradition of (political) Islam and extensive experience with religion-driven insurgency flavored by separatist overtones that has been underway in the area since the beginning of the previous decade. Occupying a strategic location on the southernmost frontier of the Russian Federation and bordering Georgia and Azerbaijan, two independent nations of the post-Soviet South Caucasus, the developments in these neighboring autonomous republics have been regarded as crucial for the prospects of the Islamist insurgency in the North Caucasus. Should the self-proclaimed Caucasus Emirate, the leading group of the Islamist insurgency in the region, establish a firm presence in Chechnya and Dagestan, the chances of the federal authorities to successfully address the ongoing political violence in its southern provinces would decrease dramatically. This would pave the way for a considerable deterioration of the security situation in the whole of the North Caucasus, with possible repercussions in Russia's other regions with significant Muslim populations.In mid-March 2012, a massive redeployment of military personnel from Chechnya to Dagestan took place. According to unofficial sources from Dagestan, between 2025,000 troops from Chechnya (primarily troops belonging to the Ministry of Interior) were moved to the neighboring republic.1 A military column including large numbers of armored fighting vehicles set out from Khankala, a military base east of Grozny, to the Karabudakhkent district of Dagestan on the outskirts of the capital city of Makhachkala. Vyacheslav Makhmudov, a spokesman for Dagestan's regional Interior Ministry, claimed that [w]e are talking about a temporary deployment and coordination to prevent and counter terrorism and extremism across the whole territory of Dagestani President Magomedsalam Magomedov further stated that this addition of troops would enable us to maintain law and order and fight extremism and terrorism more effectively.4 Rationalized by the authorities as another means of improving the deteriorating situation in the Caspian republic, this move has caused serious concern both within and outside of Dagestan. The number of troops recently redeployed to Dagestan is staggeringly high, leading to concern over whether Russia's intentions in this area may go beyond a mere attempt to stabilize Dagestan.5 There is further concern over the ethnic composition of the troops.6Broadly speaking, this article is an attempt to reveal the potential of ChechenDagestani conflict, the likelihood of which has increased recently due to the redeployment of Chechen (and Chechnya-based) troops from Chechnya to Dagestan. In particular, we seek to discern the significance of the redeployment of these troops to Dagestan. We shall initially provide some background for Chechen-Dagestani tensions in the region, the growth of the Islamist insurgency in Dagestan, and the instigation and expansion of Kadyrovization in the scope of the fight against the insurgency. We shall then introduce some possible rationales behind Moscow's troop redeployment to Dagestan as well as address some of the likely implications, both locally and regionally. Our aim shall be achieved by analyzing the motivations and repercussions of this decision.BackgroundChechen-Dagestani Tensions: A Brief HistoryApart from the traditional sense of rivalry and competitiveness, the peoples of the Caucasus, Chechens and Dagestanis - who are close to each other in both their shared culture and their history of fierce anti-colonial resistance dating back to the end of the eighteenth century - have faced incidents of conflict in the near past. The story began in 1944, when the Chechens, accused by the NKVD (Stalin's internal security agency) of collaboration with Nazi Germany, were deported en masse to Central Asia, and the politico-administrative map of the autonomous republic of Chechen-Ingushetia was redrawn, with some of its eastern territories permanently rendered to Dagestan. …

Organizational Innovation: Lessons from Military Organizations

Sociologists interested in organizational dynamics have tended to ignore military organizations, leaving these to political scientists and historians to study. This is a pity, since military organizations often serve as extreme cases of processes that occur in other kinds of organizations, thereby providing useful tests of sociological propositions. The books reviewed here are written almost exclusively by historians. They deal with a tightly focused topic: How did various military organizations respond to rapid technological change in a period of constrained resources and great environmental turbulence? They ask a series of interesting questions: Which organizations were best at innovating, and why? How important were resource constraints, past history, organizational leadership, and clarity of organizational mission in producing successful responses to change? Their answers are varied, but if a common answer exists it is this: An organizational culture conducive to open debate, and identification of a clear organizational task, together with sufficient organizational autonomy to focus on that task without major distractions, were the primary factors producing innovation and organizational adaptation. The organizations studied in these four books shared a lot of features. They were all in the same business-preparing for war. The time frame of these studies is the period between the First and Second World Wars. The First World War had seen the introduction of armored fighting vehicles (the tank), and an extensive use of the new airplane technology. These technical innovations, together with the wireless radio, would clearly change

Armored Vehicle Crew Casualties

The use of armored vehicles since the First World War has created a subset of casualties with a different epidemiology than infantry soldier casualties. The preponderance of armored fighting vehicles (AFVs) in the world's armies make their use in a future war likely. The purpose of this paper is to review the nature of possible injuries to crewmembers of these vehicles by historical and experimental data. Injuries to armored vehicle crewmembers are characterized by a large number of burn casualties, a larger percentage of fractures and traumatic amputations with extremity wounds, and a higher mortality when compared with infantry footsoldier combat casualty statistics.

An active noise reduction system for flying helmets and ear protectors

One of the major limitations of flying helmets or hearing protectors is their inability to provide adequate acoustic attenuation at low frequencies. In both fixed and rotary wing aircraft and in armored fighting vehicles, the high levels of low‐frequency noise cannot be suitably reduced by the use of passive hearing protectors alone. The development of active noise reduction for use in such protectors allows much of this limitation to be removed. This paper describes the development and testing, both in the laboratory and during flight trials, of an active noise reduction system fitted to the current UK military force's flying helmet. The system was developed under a Ministry of Defence contract by the Institute of Sound and Vibration Research at Southampton University, and assessed by the RAE in a number of helicopters and during high‐speed, low‐level flight in a strike aircraft. The results from both the laboratory testing and from the flight trials are discussed, and the operational and medical advantages of using this type of active system summarized, both for military and civilian use.