Search

Nowadays, most design processes are computer-aided, but in the case of internal ballistics they are not generally available or are highly specialized and secret. On the other hand, an analytical solution of the system of nonlinear differential equations describing the phases of the phenomenon of a shot in a gun barrel does not exist. Therefore, in order to obtain more accurate solutions to the system of equations, it is worth to use numerical methods. The paper presents a theoretical description of the problem based on a review of analytical and numerical models solving the main problem of internal ballistics. Based on this analysis, it was assumed that a possible direction of development is to implement several models to solve the main problem of internal ballistics in numerical solution, so that the end user (designer) can choose different models and check which model works best in his conditions. In addition, using optimization techniques, an attempt can be made to implement algorithms that would be able to search for example, the smallest powder weight value at specific powder parameters and at given maximum pressure and projectile muzzle velocity. The utilitarian goal of further research is to create a new analytical tool supporting the design of barrel weapons.internal ballistics, Lagrange, pyrodynamics, pyrostatics

Methods used nowadays in forensic laboratories allow to stop some kinds of projectiles with degree of deformation which lets to use them for comparing traces to projectiles found on the crime scene. However they are not useful for every type of projectiles. Comparative physical tests are enough to indicate the best method for soft catching projectiles. For this aim point of view no modeling needed. The paper presents the results of ballistic tests of impact of chosen types of soft point projectiles into water. The behavior of projectiles of various shapes, with different kinetic energy, was analyzed. On the basis of the obtained results, the projectiles with the highest susceptibility to deformation were identified. Research works described in the paper were performed within the framework of the project Laboratory stand for stopping high-energy projectiles financed from the National Centre for Research and Development (Agreement no. DOB-BIO10/04/02/ 2019). The project is implemented in cooperation with Warsaw University of Technology, Military Institute of Armament Technology and Tebbex 2 since 2019 to 2022.

The main aim of the work was the experimental and numerical analysis of the energy absorption/dissipation capabilities and failure mechanisms of novel hyper-elastic target material intended for ballistic applications including layers of composite armors, projectile catching systems and anti-ricochet layers covering walls of shooting ranges, ballistic tunnels, etc. Static and dynamic mechanical properties of the material were analyzed at both room and elevated temperatures ($$40\div 80\,^{\circ }\hbox {C}$$ 40 ÷ 80 ∘ C ). Numerical models of the material and $$7.62\times 25$$ 7.62 × 25 mm FMJ projectile were defined. Simulations of the hyper-elastic target penetration with the projectile were carried out. The differences between the results obtained numerically and experimentally were determined (measured as a relative error) and were lower than 15% what testified about proper definition of the numerical models of the analyzed phenomenon components.

The paper deals with some selected elements of a designing process for a “quiet” mortar projectile. Basing on it a decision could be made if specifications of the design were met. Numerical computations have proved that it is possible to design a quiet 60 mm mortar projectile with the range of 1200 ÷ 1300 m and own mass 1.8 kg. Moreover, the strength calculations have proved that the projectile can be made of commonly used structural materials.

The paper presents a theoretical description of computer codes for solution of the major question of internal ballistics for a “silent” mortar projectile. The computer codes proved their usefulness by providing the characteristics of a shot for each correct configuration of the projectile and eliminat-ing automatically the solutions not complying with the accepted specifications. Additionally, the structure of the code facilitates the modifications of a system of equations and parameters of the model to assisting a designing process of other systems of firearms.

Theoretical introduction into operational principles and designs of typical “silent” mortars and their ammunition is presented in the paper. The principle of operation and structure of “silent” mortar projectile are presented. In the following chapters a review of selected designs of “silent” mortar projec-tiles is included. After analysing the data the final calibre of the projectile and other key parameters to be deployed in own project were accepted. Following designing parameters were accepted in the summary: calibre 60 mm, mass of the projectile 1.8 kg, minimum muzzle velocity 125 m/s.

Numerical calculations were used to investigate influence of sabot structures of kinetic energy projectiles into the armour penetration depth. Areas of sabot structure for possible optimization and the influence of various sabot materials on the projectile combat efficiency were indicated. The analysis was performed using the finite element method in the Solidworks Simulation environment. It allowed examination of dynamic loads the sabot is subjected to at the time of the shot. Impact of various sabot materials and projectile geometry modifications on the strength of penetrator - sabot connection was investigated. Distributions of dynamical loads for penetrator-sabot connections were simulated and visualised. Calculations on terminal ballistics were performed for some options of the structure. It allowed identification of development trends for this type of ammunition.

Ammunition used by modern tanks is generally designed to fight strongly armour cladded vehicles and concentrated groups of infantry. Deployment of strongly armour cladded combat vehicles to special missions and asymmetrical conflicts is useful due to their resistance against firing by the infantry. The optimisation of used ammunition and often the development of completely new types is required for efficient use of tanks. The paper presents some studies on selected options of 120 mm kinetic energy fragmentating projectile (PELE) which can be successfully used in urban areas. A review of accessible scientific data was made to analyse possibilities for using some types of materials as components of these projectiles. Projectile’s shell was made of 1045 steel, and the cores were made of aluminium 1050 or polyamide 12.

A numerical analysis over influence of kinetic energy projectile sabot structure on the armour depth penetration is presented in the paper. The analysis has identified an influence of sabot different materials into projectile combat performance, and some areas of sabot structure where its shape can be optimised. The finite element method in Solidworks Simulation environment was used in analysis. Due to it the dynamical loads of the sabot at the time of firing could be investi-gated. The influence of sabot different materials and projectile geometry modifications on the strength of penetrator sabot joining was studied. A pattern of dynamical loads for the penetrator sabot joining was simulated and visualised. For selected options of the structure the calculations were performed over the terminal ballistics. It allowed an identification of potential development trends for this brand of ammunition.

Investigations over dependence of strength properties of material used to the core of a kinetic energy fragmentating projectile on the efficiency of fragmentation of its shell have proved that this effect may be analysed by Ansys 19.2 code and Explicit module. Firing velocities of projectile filled with aluminium were 935 m/s, 920 m/s, 874 m/s, 801 m/s corresponding to hitting a barrier at respective distances 100 m, 200 m, 500 m and 1000 m. The projectile with the polyamide core was tested only for hitting velocity of 935 m/s. It was shown that 120 mm projectile made of C45 steel and filled with aluminium 1050 or polyamide PA12 penetrates a 120 mm thick concrete wall. The projectile creates a conical crater in the barrier at penetration and next starts to fragmentate.

Thousands of debris dangerous to personnel are generated during controlled explosion of warheads containing explosives. To ensure the safety of people, it is necessary to define a zone in which people can stay without risking their lives. A major focus of modern engineering is to maximize the safety of operating technical equipment. In order to implement the above, it is necessary to determine the kinetic energy of the fragments, for which the safe level is below 17 joules (like for air gun). Simultaneous registration of the velocity of such a large amount of fragments is a significant research problem. The article presents a comparison of the two methods of measuring the velocity of splinters formed during detonation of the fragmentation generator. The first common method is to use a chronometer and aluminum foil. The second method, new for this application, is to use a Doppler radar. It allows you to measure the velocity at any moment of the path traveled by the splinter. The article also describes attempts to measure the velocity with both methods, using different variants of Doppler radar settings. Difficulties resulting from the measurements were described, as well as the methods of their elimination.

The paper describes a concept of increasing the penetration capacities of kinetic antitank projectiles, having a penetrator made of a tungsten based sinter, through the application of materials with variable mechanical characteristics for penetrator’s particular segments. The influence of alloy additions on some strength parameters for the tung-sten based sinters were assessed by using the literature data, and in the next step by numerical analyses of steel plate penetration process calculated for selected configurations of structural materials of penetrator segments. The summary describes some possibilities for modification of the structure of tungsten based sinters which may decisively improve the penetrating capacities.

During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of substrate on its strength and work during shooting should be examined. Until now in the Polish standardization documents was no clear description about the substrate parameters used for this kind of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of substrate and its geotechnical parameters. Therefore, the authors carried out analytical and experimental analysis of the use of geotechnical methods to determine the parameters of the substrate for mortar testing. The paper presents the proposed types of standardized soil and their research methods. Preliminary tests were also carried out using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the proposed methods of measuring the parameters of soil compressibility were determined.

Głównym sposobem urabiania skał w górnictwie podziemnym i odkrywkowym jest wykorzystanie materiałów wybuchowych. Optymalnym sposobem urobienia skały jest w tym przypadku wprowadzenie ładunku do otworu strzałowego. Proces wiercenia otworów w po-równaniu do załadunku i detonacji materiału wybuchowego jest najbardziej czasochłonną operacją. Dodatkowo względy techniczne mogą utrudniać lub uniemożliwiać wykonanie otworów strzałowych. Wyeliminowanie proce-su wiercenia poprzez zastosowanie ładunków kumulacyjnych może znacząco wpływać na zwiększenie postępów drążenia. Niniejsza praca ma na celu określenie możliwości wykonywania otworów strzałowych wykorzystując głowice kumulacyjne amunicji przeciw-pancernej. Wyniki przeprowadzonych badań będą służyły do opracowania, wykonania i wprowadzenia do górnictwa nowego typu ładunków kumulacyjnych, które w przyszłości umożliwią zwiększenie efektywności górnictwa przy utrzymaniu lub obniżeniu kosztów.

Protective properties of perforated plates made of modern ultra-high hardness nanostructured bainitic steel were presented in this article. The ballistic tests and the finite element modelling of the impact phenomenon were included. The 7.62 mm × 54R B-32 API and the 7.62 mm × 39 API BZ projectiles were used in the analyses. Results of both experimental and numerical studies indicated that appropriately designed holes pattern can reduce the weight of the armour by up to 40% compared to the monolithic plates of the same protection capability. A small difference between the simulations outcomes and the experimental observations confirmed that the developed numerical model allowed correct representation of the analysed phenomenon. The finite element modelling together with the developed probabilistic model of optimization of holes distribution constitute a fast, robust and effective tool that can be used in parametric studies to maximize the efficiency of perforated armour systems.

The article presents development of battle tanks armours during the last 100 years on the base of literature review considering aspects of the advancement in defence technologies and the threats of asymmetric and full scale military conflicts. Selected designs of tanks which were in the service were studied to assess defence capacities of tank armour systems and their resistance against penetration by kinetic am-munition.

The phenomenon of creation of adiabatic shear bands occurring at extreme strains of investigated material is analysed in the paper. The effects of penetration for projectiles made of depleted uranium and tungsten sinters were compared to analyse an influence of the adiabatic shear bands into the process of penetration and to show some possibilities for structural modification of tungsten sinters increasing the penetration capabilities. The comparative analyses were conducted on the base of literature review.

Finite element modeling of ballistic impact of inserts containing titanium structures were presented in the article. The inserts containing an additional layer made using additive manufacturing technology were analyzed. The layer was created from repetitive elements made without connections (adjacent cells were inseparable). Four variants of printed titanium structures were placed between layers of Twaron CT 750 aramid fabric to create ballistic inserts. In order to assess the ballistic resistance of the inserts, numerical simulations of ballistic impact phenomenon were carried out using LS-Dyna software. In the simulations the inserts were placed on a steel box filled with ballistic clay and were fired at with the 9 &acute, 19 mm full metal jacket (FMJ) Parabellum projectile. The main aim of the work was to check the effectiveness of such solutions in soft ballistic protection applications and to select the most effective variant of 3D printed structure. Results of the numerical analysis showed a high potential for 3D printed structures made of titanium alloys to be used for bulletproof vest inserts. In all analyzed cases the projectile was stopped by the armor. In addition, thanks to the cooperation of adjacent cells, the projectile energy density was distributed over a large area, as evidenced by large volumes of hollows in the ballistic clay. The indentations in the ballistic clay obtained in the simulations were significantly lower than the acceptable value for the back face deformation (BFD) parameter required by international body armor standards.

The paper presents the results of studies on the effects of shooting composite materials produced by pressure infiltration with the EN AW-7075 alloy as a matrix and reinforcement in the form of preforms made of &alpha, Al2O3 particles. Composite materials were made with two reinforcement contents (i.e., 30% and 40% vol. of &alpha, Al2O3 particles). The composites produced in the form of 12 mm thick plates were subjected to impact loads from a 7.62 &times, 39 FMJ M43 projectile fired from a Kalashnikov. The samples of composites with different contents of strengthening particles were subjected to detailed microscopic examination to determine the mechanism of destruction. The effect of a projectile impact on the microstructure of the material within the perforation holes was identified. There were radial cracks found around the puncture holes and brittle fragmentation of the front surfaces of the specimens. The change in the volume of the reinforcement significantly affected the inlet, puncture and outlet diameters. The observations confirmed that brittle cracking dominated the destruction mechanism and the crack propagation front ran mainly in the matrix material and along the boundaries of the &alpha, Al2O3 particles. In turn, numerical tests were conducted to describe the physical phenomena occurring due to the erosion of a projectile hitting a composite casing. They were performed with the use of the ABAQUS program. Based on constitutive models, the material constants developed from the identification of material properties were modelled and the finite element was generated from homogenization in the form of a representative volume element (RVE). The results of microscopic investigations of the destruction mechanism and numerical investigations were combined. The conducted tests and analyses shed light on the application possibilities of aluminium composites reinforced with Al2O3 particles in the construction of add-on-armour protective structures.

A second generation kinetic energy APFSDS-T projectile with segmented penetrator developed in the Military Institute of Armament Technology was tested to verify the strength of the design and identify the basic ballistic characteristics of the cartridge and present some results in the paper. The firing test was carried out on the artillery range in Nowa Dęba on 12 October, 2017

Basic models applied for analysing and modelling the flight parameters of projectiles were disscussed in the article. A modified model with five degrees of freedom and neglection of the sixth one, representing the projectile rotation speed, is proposed by authors on the basis of conducted analysis to analyse flight parameters of a supersonic mortar projectile. To obtain the coefficients required in the modified model the CFD methods (ANSYS FLUENT software) were used.

During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of terrains on its strength and work during shooting should be examined. Until now, in the Polish standardization documents there was no clear description of the ground parameters used for these kinds of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of ground and its geotechnical parameters. In view of the above, it has become important to draw up a research problem in the form of determining the types of soil with parameters, enabling the mortar tests to be carried out in conditions as close as possible to combat conditions. Therefore, the authors carried out the theoretical calculations and field tests with the use of geotechnical methods such as static and dynamic load tests to determine the parameters of the ground for mortar testing. Preliminary tests were conducted using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the tested methods of measuring the parameters of soil compressibility were determined.

The paper presents simulation of flight path of a lead ball fired with an arquebus and its penetration process through an armor of heavy cavalry knights of the beginning of the 16th century used during the Battle of Pavia on 24 February, 1525. The mass use of firearms by the footmen against the cavalry decided the result of the battle and started a large deployment of infantry formations armed in firearms. The basic ballistic characteristics of 16th century arquebus necessary for the simulation process are based on historical information. The numerical calculations were used to identify the flying characteristics of the lead ball at the distances securing the penetration of that time horseman’s armour. Penetration capacity of the lead ball through the 16th age horseman armour was estimated by using the finite element method (AUTODYN).

The paper presents simulation of flight path of an arrow shot with a longbow and its penetration process through a steel plate imitating an armor of a medieval heavy cavalry knights used during the Battle of Crécy on 26 August, 1346. The battle was a turning moment which had settled the specific role of the English bow in tactics and methods of its deployment on battle fields for almost 200 years until the firearms such as arquebuses or muskets started to be commonly used. The basic technical parameters necessary for the simulation process are based on historical information. On the basis of numerical calculations, the parameters of the flight path of the arrow with the "anti-armor" head were determined up to the maximum range. Thanks to use of the finite element method (AUTODYN) the penetration capacity of the arrow shot from longbow against horseman’s armor of XIV century was estimated.

A mathematical-physical model of the hypersonic anti-tank kinetic subcalibre projectile for 120 mm munition was built. Computer simulations of the projectile flight were performed for any angle of shooting, from 0° to 90°. Trajectories of projectile flights were determined considering all angles of shooting. Theoretical calculations were verified by experimental measurement of the projectile velocity in time while shooting on a test range. Some conclusions with regard to safety during hypersonic projectile shooting on the test range were formulated.

Basic energetic parameters of select-ed examples of 120 mm APFSDS (armur piercing fin stabilised discarding sabots) service projectiles are specified and analysed in the paper. Author has estimated chances for meeting penetration capacities through RHA (rolled homogeneous armour) by designs of kinetic energy projectiles which are currently under development. The summary also includes a characterisation of present limitations for tank guns ballistic parameters.

Results of comparison between drag coefficients established by the firing tests and numerical simulations are presented in the paper. The results of numerical calculations carried out by CFD method, exploiting Ansys Fluent v16 software, were used to develop initial firing tables for newly designed projectiles for RAK mortar.

The basic goal of this project it to check the possibility of use warheads of the demobilized cumulative ammunition for sinking tunnels or channels in the mining. The preliminary tests were conducted in Military Institute of Armament Technology with using warheads of the battle ammunition.Dynamic tests were conducted on 26 June and 18 September of 2015 year on the training ground of the Military Institute of Armament Technology in Zielonka near Warsaw. The possibility of the penetration of concrete structure by cumulative warheads of the combat ammunition was a purpose of research.

In this paper, the authors presented an analysis of the strengthening of the cumulative jet by the appropriate formation of the detonation wave front acting under the influence of high pressure on the liner. The analysis of the Polish ŁK cumulative charge was carried out using numerical methods in the ABAQUS program. Simulation studies were carried out on axial and peripheral initiations of the explosive cumulative liner. For this purpose, two types of cumulative charges were made with the same design parameters, differing only in the explosive detonation-initiation system. The impact of the elastomer insert on the focusing of the cumulative jet was verified. The influence of peripheral and axial initiation on a cumulative jet&rsquo, s velocity was investigated. The authors proposed a new conical insert placed in the explosive between the pocket for the detonator and the liner, also changing the material of the cumulative liner. The smoothed-particle hydrodynamics method was used to describe the formation of a cumulative jet. The obtained results were verified experimentally, and they show that modification of the ŁK charge has a positive effect on jet amplification, with an inevitable collapse in the final stage of formation. The obtained results correlate with the literature&rsquo, s data.

In this paper, we present the constructions and reliability firing tests of the special ammunition for M-98 mortar. The research and development works was being carried out as part of the projects No. 347 / BO/B and 348 / BO/B. Qualification firing tests was carried out in 2009 on the training ground in Nowa Dęba. Cartridges with the smoke projectile are intended for filling the area with smoke, indicating targets, protection of the maneuvers of own troops. Cartridges with the illuminating projectile are intended for lighting the area and indicating targets. Reliability firing tests was carried in November 2014 on the training ground in Nowa Dęba

The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity) as a function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it's particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot) and tungsten alloy (penetrator) are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2·104 s-1 (for aluminium alloy) and 6·103 s-1 (for tungsten alloy).

This paper discusses the general conditions relating to ballistic head protection, analyzing the risks that may occur on contemporary battlefields. A thorough literature review has enabled us to present development trends for helmets used in the largest armies in the world. The authors have focused on impacts to the helmet shell, overloading the entire helmet-protected head&ndash, neck system. The main objective of this study is to investigate the protective capability of a helmet shell when subjected to projectile&ndash, helmet contact, with contact curvature taken as being an indicator of the impact energy concentration. Blunt head trauma was estimated using backface deformation (BFD). The Wz.93 combat helmet was used for testing. Analytically, dependencies were derived to determine the scope of BFD. A five-parameter model of the helmet piercing process was adopted, thus obtaining the optimal BFD range. Verification of theoretical considerations was carried out on a specially developed research stand. In the ballistic tests, dynamic deflection of the helmet&rsquo, s body was registered using a speed camera. On the impact testing stand, a fragment of the helmet was pierced, producing results in the low impact velocity range. Data have been presented on the appropriate graph in order to compare them with values specified in the relevant standard and existing literature. Our results correlate well with the norm and literature values.

A problem of the dynamics of long-rod penetrators loaded with the gunpowder combustion products has been solved in closed form by using the wave method (d’Alambert). The analytic recurrence formulae have been derived to define the fields of longitudinal stress and particle velocity in the rod penetrator. The problem of estimating the axial stress field and particle velocity caused by the gunpowder combustion products for a subcalibre projectile penetrator has been solved by using the substitute dynamic theoretical model. The reason for using the substitute dynamic theoretical model is that the pressure on the rear part of the projectile is controlled by gas-dynamic processes and it is not possible to readily estimate the loading. The method of characteristics net gets very complicated.

In this paper we present possibilities of increasing the depth of penetration through a steel plate by using segmented kinetic energy penetrators. Conclusions about the possibilities of increasing the penetration depth were formulated based on the critical review of the literature, simulations, and firing test results. A new concept called “forced segmented penetration,” where applied penetrator is composed of two tungsten alloy pieces connected by a screwed steel muff, is presented in this paper. The axial deformation of the connecting muff during the penetration process results in a decrease in the distance between tungsten segments. For this reason the rear segment can hit the front segment to give it some additional kinetic energy, enhancing the penetration depth. Such type of segmented penetration phenomena was not presented earlier. The numerical analyses of the segmented penetrator of the new design are presented in this paper.

The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity) in function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it's particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot) and tungsten alloy (penetrator) are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2 · 10 4 s −1 (for aluminium alloy) and 6 · 10 3 s −1 (for tungsten alloy). with the range and the strain rate caused by dynamic loads in the wide range of temperatures allows to create the computer code reflecting in computer simulations the real dynamic processes of material deformation for high strain rates. The measurements of mechanical properties of constructional materials are taken during tensile, compres- sion or torsion tests of material specimens. During tests conducted on standard testing machines the mechanical parameters of material are determined at average strain rate of 5 s −1 . By using testing machines of special design it is possible to determine the mechanical parameters of mate