Gun Mount Research Articles

SCIENTIFIC AND METHODOLOGICAL APPROACH TO DETERMINING THE DEGREE OF DANGER OF AN AIR TARGET BY CREW OF A COMBAT VEHICLE WITH A TURRETED MACHINE GUN

In the course of hostilities in eastern Ukraine, the main threat to critical infrastructure is posed by airborne attack weapons, in particular, the “Shahed-136” kamikaze drone and its russian counterpart, the “Geranium-2”. A combat vehicle with a turreted machine gun mount, which is part of mobile fire groups, has a limited number of means that provide high-quality visual observation, detection and recognition of air targets. Therefore, the task of determining the degree of danger of a detected and recognized drone is relevant in order to make an adequate decision on its destruction. The paper considers methods for detecting and recognizing an aerial target, determining its angle and direction of movement by the human visual system using optical and electronic devices and optical means of visual observation. The article proposes a scientific and methodological approach that allows detecting and recognizing an aerial target such as a kamikaze drone and determining the degree of its danger, which minimizes the time for the commander of a combat vehicle equipped with turreted machine guns to make a quick and adequate decision on destruction.

Modal Research on Photoelectric Turntable of a Medium Caliber Tracked Anti-aircraft Gun

Aiming at the problem of violent vibration of the photoelectric turntable caused by the high frequency firing work load during the firing of a medium caliber tracked anti-aircraft gun, the tracking accuracy of the photoelectric tracker is unstable, and the law of the vibration of the gun on the platform is obtained by combining mechanical simulating and experiment. According to the finite element theory, a model of certain type of the gun is built, modal analysis is carried out through the ANSYS Workbench, the natural frequency and mode shape of the turntable are gained, and the hammering method modal test is carried out to verify the simulation outcomes. Through the strength check of the gun mount assembly under three typical working conditions, the weak link in the structural design is found. The results show that the research results can provide a reference for the structural design optimization of the photoelectric turntable on a vehicle-mounted antiaircraft gun.

Experimental study on continuous firing vibration response of the typical machine guns under different ground conditions

In order to study the influence of ground conditions on the continuous firing vibration response of typical machine gun, and find out under which conditions the machine gun is most stable. A high-speed photography method was used to measure the motion of multiple parts. The motion curve of each part in the shooting process are obtained, and the projectile dispersion are recorded. According to the results, the motion characteristics of each part is analyzed. The pitching and translational quasi-periodic motions of the whole gun under different ground conditions are compared by synthesizing the motion data of various parts. The working modes of gun tripod under different ground conditions are discussed, and are compared according to the corresponding projectile dispersion. The result show that, in quasi-periodic pitching motion, the upward pitching motion response of the gun under the condition of cement ground is large, the ability to restore the initial position is poor, and the corresponding vertical dispersion is the worst. Under the soil condition, the upward and downward pitching motion cycle of the gun is relatively stable, the ability to restore the initial position is strong, and the corresponding vertical dispersion is the best. In terms of quasi-periodic translational motion, the translational motion of the gun mount under the cement ground is the biggest, and the corresponding horizontal dispersion is also the biggest. Under the soil ground condition, the translational motion is the smallest, and the corresponding horizontal dispersion is also the smallest.

Topological optimization of the stiffness of an irregular structure based on an element size independent filter

Because of the overly averaged element sensitivity in the topological optimization of an irregular structure with a grid independent filter, a topological optimization model was built for the structural domain. The maximization of stiffness was first taken as the goal for the topological optimization of irregular structure stiffness. Subsequently, an element size filter was proposed to address the overly averaged local element sensitivity with the grid independent filter when the designed domain element size varied dramatically. Finally, the element sensitivity of the objective function was derived under the given constraints. A case study was then conducted on a naval gun mount with the maximization of structural flexibility as the objective function and the volume of structural material as a constraint. A stiffness optimization model based on the bi-directional evolutionary structural optimization algorithm was adopted for the topological optimization of the gun mount. Structural optimization was conducted for the gun mount with different shooting angles to realize its optimal stiffness and strength under the constraint of consistent material volume. The optimization results proved that the element independent filter proposed in this paper could be effectively applied in the topological optimization of an irregular structure and used to explore the topological optimization of the supporting structure under impact.

Modal Optimization Design of Supporting Structure Based on the Improved Particle Swarm Algorithm

To cope with the strong vibration of a supporting structure excited by external loads under operating conditions, and in order to achieve the purpose of vibration reduction by structural optimization through modal modification, a modal modification method was proposed, through structural vibration theory. Subsequently, the search performance of an improved particle swarm optimization method was analyzed before conducting a case study on the structural optimization. Finally, aiming at the problem of strong vibration of gun mount at the time of firing, a finite element model of the gun mount was constructed and the type and natural frequency of the gun vibration in a free state was analyzed. Meanwhile, taking the thickness, height and width of the stiffening structure of the bracket as the design variables, combined with the improved particle swarm algorithm, an optimized mathematical model was developed with the first-order natural frequency of the gun mount as the objective function. The secondary development of Abaqus finite element software by using Python is used as a tool to calculate the optimization model. By virtue of optimation, thickness, width and height of the stiffening structure are 156.4mm, 453.7mm and 238.9mm at the range of [100,600]mm, [100,700]mm, [100,700]mm, respectively, and the base frequency of the gun mount has been increased by 11.3%. The effect is remarkable.

Mathematical Modeling of Heat Friction Contact Master Belt with the Gun Mount Barrel During the Process of High-Speed Motion

The friction in the gun mount barrel at sliding speeds of artillery projectile 500 - 700 m/s is not sufficiently studied. The main problem is to increase the efficiency of the master belt with a significant increase of the interaction parameters of the barrel with the projectile. To determine the effect of heating on the change of physical and mechanical properties of the surface layer and friction coefficient on the surface of the master belt were made mathematical modeling of heat transfer.

Transient Dynamic Finite Element Analysis of the Air-defence Weapon System Mount Assembly of Tracked Vehicle

A detailed finite element model of the existing Air-Defence Weapon System (ADWS) mount assembly of a military tracked vehicle, has been developed in Abaqus/CAE and modal dynamic analyses have been carried out. A mathematical vibration model of the gun recoil system has been developed in Matlab, in order to estimate the transmitted force variation during gun firing as well as the gun recoil. The frequency spectrum of transmitted force variation, has been analysed in correlation with extracted eigen values of the mount assembly, followed by dynamic analysis during rapid firing of 5 rounds. Based on modal dynamic analysis, required design modifications have been carried out by stiffening the mount structure at appropriate locations, and firing accuracies were obtained within acceptable limits. This study would be a useful approach to design of any gun mount assembly.

Stress analysis of integrated 12.7 mm machine gun mount

Stress analysis of integrated 12.7 mm machine gun mount

Баллистическая бикалиберная установка с деформируемым поршнем

Баллистическая бикалиберная установка с деформируемым поршнем

The Vibration Modal Testing and Analysis of an Experiment Gun Mount

An experiment gun mount system is used to clamp the small arms and replace gunner to conduct the automatic shooting in the shooting accuracy test. Because of the concomitant phenomena such as high shock and vibration when shooting, to study the vibration characteristics of the system, a modal analysis method was proposed and the experimental points, including the exciting points and the vibration pickup points, were determined on the basis of its geometric model. Based on the Fast Fourier Transform technique, the CRAS modal testing system was built. The modal experiment of the system was carried out by hammer blow method. The exciting signals, spectra of impacting prompt power, vibration acceleration and their frequency response functions were obtained. The first six order vibration modes, damping ratio and the corresponding vibration frequencies were obtained, which laid the foundation for dynamic response calculation and further optimization design of the system in the future.

The Gun and Corsia of Early Modern Mediterranean Galleys: Design issues and rationales

An early modern Mediterranean galley carried its main piece of artillery on a wheelless mount inside the raised centreline gangway (the corsia). The gun mount stood on two well-lubricated rails that sloped downwards from fore to aft. In its firing position, the gun was in the bows and when fired recoil propelled it all the way to the mainmast, where it collided with a stout buffer placed there to prevent damage to the mast. After reloading the gun in that position, the crew hauled it back to the bows. Several tons of bronze and wood travelled more than 10 metres back and forth with every shot. Yet instead of breeching ropes to restrain the motion, galleys had lubricated and tilted rails that expedited it. A functional examination of the fire–load–fire cycle and a technical analysis of the recoil mechanism provide the rationale for this apparently peculiar mode of operation and expose the purposes for the lubrication and slope of the rails.

Improved Design and Analysis for Static Stiffness of the Gun Mount

As the supporting parts of artillery, the stiffness of the mount has a great impact on the shooting accuracy of the artillery. The mechanical model and evaluation of gun mount static stiffness analysis are proposed. According to the initial design for a typical artillery mount, the finite element model is established and the simulation analysis of the mount static stiffness are carried out, stiffness properties, contours of displacement and stress of the gun mount are obtained. The deformation characteristics and the weak parts of the gun mount in different conditions are discussed. Based on the deformation characteristics and the weak parts, a satisfactory design is obtained with the strategy of "improvement- assessment- improvement". Compared with the original design, the stiffness has a relatively large increase with the weight increasing slightly. The study has a positive effect for analysis and design of the mount static stiffness.

Advanced Gun System Gun and Projectile Dynamic Model Results and Correlation to Test Data

BAE Systems is currently developing and testing a 155 mm advanced gun system (AGS) and a long range land attack projectile (LRLAP) as a part of the DDG-1000 ship development program. For this development, it is important to understand the barrel and projectile dynamics, including the interaction of the barrel and the projectile in the bore as well as the projectile tip-off parameters at exit. An abaqus explicit dynamic finite element model has been developed to compare results with test data that were taken on June 18, 2003, at the BAE Systems site at the Alliant Techsystems Proving Ground (ATPG) during AGS propellant testing. The abaqus model includes the gun barrel, the projectile used for propellant testing (a steel slug), the M110 gun mount, and the recoil system. Features of the model incorporate settling of the barrel due to gravity, gun recoil, in-bore interaction of the projectile and the barrel using contact surfaces, and the initial flight of the projectile after bore exit. The abaqus model results have been compared with gun firing test data acquired during propellant testing at Elk River, MN. These comparisons include barrel and projectile displacements, angular velocities, and axial accelerations. The abaqus model results are also compared to similar models of the test conditions with the simulation of barrel dynamics (simbad) gun dynamics code and the ibhvg2 interior ballistics code.

A Friction Model Describing Limit Cycles in Positioning Servos

In this paper we describe a novel model for servo positioning systems. Non-linear representations of friction, backlash, controllers, and process dynamics are integrated into a model having a closed-loop configuration where unwanted oscillations, such as hunting (stick-slip) and resonant frequencies, are reproduced. This continuous model contains the different types of friction (Coulomb, Stribeck, and viscous) and the dynamics of a digital controller with a standard configuration. A case study consisting of a gun mount driven by hydraulic actuators is analyzed. Real data is used for the identification and validation of the mathematical representation. Empirically obtained static friction values are used for tuning the model at low speeds. An excellent matching is accomplished between the model and the real response. The model also reproduces the dependence of the resonant frequencies to the rotating velocity that is generally observed in this type of feedback system. The model can be a powerful tool for testing new control strategies. It looks for reductions in oscillation, predicts limit cycles, and detects faults.

Modelling end-of-roll dynamics in positioning servos

End-of-roll dynamics is a characteristic of pointing systems and positioning servos when change in movement direction occurs. Factors such as backlash and friction cannot be easily controlled nor predicted under these circumstances, and although an accurate model for friction exists, the literature is still lacking of a representation for the integrated effect backlash and friction dynamics in these loops. This paper proposes a new mathematical model to represent backlash effects in positioning servos demonstrating its accuracy to predict tracking errors of a naval gun mount. The model introduces a continuous hysteresis representation, different from classical discontinuous models, showing a behaviour closer to what has been observed empirically. The new model can be useful for high performance positioning servo-control applications.

Preliminary Design of Tracking Loop for Marine - Used Machine Gun.

This study develops conventional use of 20 mm twin machine gun to provide defence against close-in-air threat. For expanding the field of usage of machine gun and promoting defence ability in naval combat, this study offers a preliminary design of tracking loop, which includes the man-in-loop's scheme. Accuracy and stabilisation are the main considerations for a shipboard weapon design and are included in design. In numerical simulations, the stabilisation of gun mount and carriage platform in tracking loop under large disturbances induced by sea waves is assessed first. Two typical scenarios proceed with the testing of tracking performances. Simulation results demonstrate the effective performance of designed tracking loop subject to environmental disturbances.

Navy High Energy Laser Weapon System

ABSTRACTThis paper will historically review and describe the Navy High Energy Laser Weapon System (HELWS).Advances in anti‐ship cruise missiles (ASMs), which present the greatest challenge in surface ship self defense, are necessitating the development of significantly more sophisticated and expensive surface‐to‐air missiles in order to counter the threat. The next generation of ASMs, as represented by the French ANS, will be capable of skimming only meters above the sea surface at multi‐mach speeds, while performing evasive maneuvers during terminal run‐in. This type of threat has essentially eliminated naval gun systems from the role of ship self‐defense, and has significantly reduced the effectiveness of current missile systems.Under development for the past twenty years, the High Energy Chemical Laser appears to be a feasible solution to the ship self‐defense problem. Capable of operating effectively in all weather conditions except dense fog, a HELWS requires no conventional fire control solution, since it operates at the speed of light. Any target that can be tracked can be engaged. Furthermore, once the beam director is locked onto a target, the system is insensitive to target maneuvers. By tailoring the lase period to the threat, the effective Pk of an HELWS is essentially 1. Using chemical energy as a primary power source removes the requirement for additional costly and heavy power generation equipment aboard ship. In the context of the foregoing arguments, cost per kill becomes a fraction of the cost of a two‐round missile salvo.The technology required to field a shipboard HELWS has been demonstrated by the Navy Mid‐InfraRed Advanced Chemical Laser (MIRACL) and the Sea Lite Beam Director (SLBD). Its success in bringing down a Mach 2.2 Vandal missile in 1989 was dramatic proof of the effectiveness of such a system. Recent studies have shown that the MIRACL/SLBD can be repackaged as a HELWS to fit into the equivalent volume occupied by a 5“/54 Mk 45 gun mount and its associated magazine. Replacing the gun system with this HELWS package would result in a 15 percent reduction in weight and translate to a 5 percent improvement in ship stability because of the weight redistribution.The one remaining issue is an operational demonstration of the High Energy Laser Weapon System in a shipboard environment. The Navy is currently studying the possibility of conducting an advanced technology demonstration of a shipboard HELWS to begin in FY 95. Such a demonstration will be designed to resolve the remaining issues associated with using high energy lasers for self‐defense at sea.

Chlorotrifluoroethylene oligomer based nonflammable hydraulic fluid. 2 Hydraulic components' development

AbstractA requirement for a nonflammable hydraulic fluid was defined in the 1970s to eliminate losses attributable to hydraulic system fires. In order to increase the possibility of success of the nonflammable hydraulic fluid development programme, requirements for compatibility with current hydraulic fluids, seals, and system designs were not established. All previous attempts to develop a compatible nonflammable hydraulic fluid had been unsuccessful. Extensive screening of many chemical classes of candidate base fluids led to the selection of a Chlorotrifluoroethylene (CTFE) oligomer. Considerable hardwarel system development was performed for hydraulic system applications, including development of high‐pressure actuators, pumps, and motors. The major thrust of the programme, a totally new system design, was demonstrated in the Lockheed High Technology Test Bed air craft and in the McDonnell Douglas Aircraft 55.2 MPa (8000 psi) technology ‘Iron Bird’ demonstrator. Possible retrofit applications for current systems include a C135E fireproof brake system and the M1/M1A1 Abrams tank gun mount. This paper also discusses material compatibility requirements, design considerations, and the results of pump testing of the nonflammable hydraulic fluid.

New Techniques in Weapon Firing Cutout Zone Design

Weapon pointing and firing zones are critical operational parameters which directly affect the safety and capability of weapon performance and ship mission. These zones are normally implemented in the weapon system and restrict areas of weapon movement and function allowing clearance for ship structure during weapon performance. The primary purpose of the zones is to ensure topside safety by preventing the weapon from firing into surrounding ship structure. Weapon pointing and firing zones are also used to integrate weapon and other shipboard equipment functions to avoid interference conflicts. The Naval Surface Warfare Center (NAVSWC) is the technical direction agent which designs weapon pointing and firing zones for every large caliber gun mount and rotating missile launcher on U.S. Navy ships. Because of the increasing complexity of topside operations and applications in computer technology, new methods are being developed to support NAVSWC weapon zone design efforts. This paper first summarizes present techniques in NAVSWC weapon zone analysis and design. The second part of the paper describes methods under development using graphic computer systems to conduct safety analyses for weapon zone design. The paper concludes with a review of future weapon cutout system improvements.

System Complexity versus Human Capabilities: A Data Base to Close the Widening Gap

A relatively large data base was developed to address the following issue: Problems in the operation and maintenance of increasingly sophisticated weapon systems have mandated a new design philosophy—manpower must become a design tradeoff variable, just like performance, cost, reliability, size, weight, etc. However, to make manpower a genuine design tradeoff variable, data are needed concerning the impact of various design alternatives on manpower parameters, like skill level requirements, maintenance manhours, etc. These data were collected and are presented in Design Guide to Operator and Technician Requirements, which covers several Navy weapon systems. Three types of data are presented in the design guide: The first is the estimated impact of 66 design alternatives on operator proficiency, maintainer proficiency, maintenance manhours, system initial acquisition cost, and system life cycle cost. These estimates were provided for four types of electronics-intensive systems by highly experienced, senior designers. Experienced senior technicians provided estimates for the same parameters, except costs. The second type of data covers the descriptive characteristics of technicians that operate and maintain the electronic systems. These profiles are to educate bench-level designers in industry, who often have little understanding of the capabilities of system users. The third type of data is a set of “lessons learned” from existing systems. Based on surveys of senior technicians, these data include: (1) profiles of the percentages of technicians at each of three paygrades who can perform selected operation and maintenance tasks without supervision; (2) the attribution of specific problem tasks to faulty design, inadequate manuals, or inadequate training; and (3) statements of specific design problems and recommended changes for problems caused by faulty design. The design guide currently comprises six volumes. Volume 1 presents an overview of the entire series, a procedure for using data from the other volumes to perform design tradeoff analyses, and a collection of comments by designers (which is a necessary reference for interpreting the data correctly). Volumes 2-5 present data for specific types of electronic weapon systems. Volume 6 is a technical report that documents the procedures used in acquiring and analyzing the data. Full titles and DTIC ordering numbers are as follows: • Design Guide to Operator and Technician Requirements: Volume 1. Overview for Surface Ship Electronic Systems. (AD-B073 358L) • Design Guide to Operator and Technician Requirements: Volume 2. Surface Ship Sonar. (AD-B073 359L) • Design Guide to Operator and Technician Requirements: Volume 3. Surface Ship Search and Navigation Radar. (AD-B073 360L) • Design Guide to Operator and Technician Requirements: Volume 4. Gun and Surface Missile Fire Control Systems. (AD-BO73 361L) • Design Guide to Operator and Technician Requirements: Volume 5. Gun Mount and Launcher Control Systems. (AD-B073 362L) • Design Guide to Operator and Technician Requirements: Volume 6. Research Leading to Guide Development. (AD-B073 363L) This work was sponsored by the Navy Personnel Research and Development Center, San Diego, California, Code 17.