Military Institute of Armament Technology

This paper focuses on the research status, application scenarios, and future development trends of ceramic matrix composites in the energy and environmental fields. It elaborates on the applications of Al₂O₃ ceramic composites, glass-ceramic composites, etc., in energy storage, conversion, and environmental protection, and analyzes the problems and challenges they face. Through the research on different types of ceramic matrix composites, the aim is to provide references for their further development in the energy and environmental fields and promote the wide application of these materials in relevant fields.

Abstract The Atkins model has been widely adopted for determining mechanical properties of wood, such as fracture toughness and shear yield stress, which are typically normalised by global density for cutting force and power predictions. This study explores the feasibility of determining these mechanical properties for knotty and clear Scots pine (Pinus sylvestris L.) using local densities revealed by X-ray computed tomography scanning. Six wood workpieces, three from Poland and three from Sweden, were scanned and subsequently cut on a custom single-tooth quasi-linear cutting machine. Cutting forces for both clear and knotty regions were recorded and normalised by local densities. Results indicate that clear Polish pine exhibits higher local-density-normalised fracture toughness and shear yield stress than Swedish pine, suggesting that wood origin influences mechanical properties beyond mere density differences. Knots display significantly lower local-density-normalised shear yield stress compared to clear wood, despite their higher density. The large variation in normalised fracture toughness observed in knots is attributed to differences in cutting direction relative to knot orientation. The study highlights the effectiveness of computed tomography scanning to provide detailed insights into wood density and structure, enabling more accurate normalization of cutting forces and enhancing the understanding of wood machinability across different origins and structural characteristics.

Abstract This study addresses the critical need for lightweight and effective ballistic protection in military applications, focusing on layered composite systems designed to meet NATO STANAG 4569 Level I standard. The layered ballistic protection combines Hardox 450 wear-resistant steel with Twaron CT 747 para-aramid fabric and Endumax Shield XF33 Ultra-High-Molecular-Weight polyethylene (UHMWPE). Three configurations of ballistic protection were evaluated, each differing in steel thickness and areal weight. Configurations 1 and 2, with 6-mm and 4-mm Hardox 450 steel, and areal weights of 84.3 kg/m 2 and 68.6 kg/m 2 , respectively, successfully resisted 7.62-mm NATO FMJ M80 projectile impacts while maintaining structural integrity. Configuration 3, comprising 2-mm Hardox 450 steel (52.9 kg/m 2 ), was not penetrated by the projectile but detached from the frame due to localized impact near the edge. Microscopic analysis identified delamination and cracking of the reinforcing fibers and matrix as dominant failure mechanisms. Combining experimental testing with numerical simulations confirms that these layered protection systems offer high ballistic resistance while maintaining low weight, offering significant advancements in the design of military vehicle protection systems.

Contemporary armed conflicts are characterized by the increasing use of unmanned aerial vehicles (UAVs). One key approach is firearm-based defense. This paper presents the concept of an innovative trainer based on augmented reality (AR) technology. The system integrates a virtual environment generated by the Unreal Engine in real-time (including realistic models of drones and firearms) with real-world maps displayed through HoloLens 2 glasses. The paper covers the technical design and implementation, enabling battlefield simulation. The prototype includes features such as dynamic training scenario generation, real-time user position synchronization, and realistic UAV behavior simulation. Findings highlight AR’s potential in military training while addressing challenges like GPS integration and cross-environment synchronization. The system demonstrates selected capabilities for the future of military training.

In the introduction of this article the „k” nearest neighbors method is presented, which can be use both for classification and regression tasks. The process of designing and built the model of the „k” nearest neighbors method was characterized, noting the lack of a generalizing model for the analyzed problem in the method and the possibility of making predictions for new predictor values. Based on the diagnostic laboratory test results, the „k” nearest neighbors model was designed for artillery igniters of the KW-4 type. The predictors and input parameters were specified, on the basis of which the proprietary model was built in the „k” nearest neighbors method. The obtained form of the model was analyzed in terms of the validity of the cross-test and the value of the number „k”. Further models were also built according to the „k” nearest neighbors method for other artillery igniters and for RGM-6 fuses, the results of which were much worse than the KW-4 igniters. Finally, the model was designed according to the input parameters suggested by the Statistica software. The model built in this way turned out to be the optimal model from the point of view of the obtained initial indicators and it should be implemented for use.

The global virtual reality (VR) market is growing surprisingly fast. As VR applications continue to expand into various areas of life, attention is being paid to issues related to user well-being. The danger lurking for users is the occurrence of simulator sickness and artificial reality sickness, collectively referred to as sensory conflict. As early as the 1950s, an attempt was made to study simulator sickness. Unfavorable psychophysical symptoms occurred in pilots using the first flight simulators. With the development of technology, the graphic and simulation capabilities of the various types of simulators are increasing. Easier access to simulators using first person view (FPV) and thus more outstanding research capabilities allow new studies related to the incidence of this disease to compare symptoms occurring during simulator sessions with those occurring during real-world endeavors. The primary purpose of the review is to bring together the latest reports on different types of sensory conflict concerning factors that are symptomatic in prediction and diagnosis. Heart rate, brain activity, stomach activity, and skin conductance seem to be the most adequate, objective indicators of subjects' susceptibility to this phenomenon. In addition, it is intended to systematize concepts related to sensory conflict in the broadest sense.

The research goal of the work was to determine the influence of thermal and mechanical processing on the fragmentation of 120 mm projectiles for the Rak self-propelled mortar based on the results of dynamic tests on the fragmentation of projectile shells and measuring the number of fragments in individual mass groups. The main issues raised in the work are the tactical and technical requirements that must be met by HE (high explosive) mortar rounds, focusing on the properties influencing on the fragmentation process of the projectiles, i.e. the material of the shell and the explosives. In order to obtain appropriate data to be studied in the work, it was necessary to test prepared research objects. Testing part includes a ballistic examination of the fragmentation of HE projectile shells, which were made of three types of materials and were subjected to various heat treatment parameters during the production process. The obtained results of ballistic fragmentation tests of mortar shells were used for analysis and enabled comparison of fragmentation characteristics between shells made of different materials and subjected to heat treatment processes. Part II presents ballistics tests on the fragmentation of mortar shells and the analysis of the obtained results.

The aim of this work was to design a sports submachine gun based on a review of current design solutions used in this type of weapon and to create preliminary technical assumptions. The scope of work included the selection of a cartridge for the submachine gun, the selection of the barrel length, the calculation of the outer diameter of the barrel, the selection of the mass of the bolt and the return spring as well as the calculation of the bolt kinematics, and the preparation of a functional model using the additive technique, checking the correct operation of the weapon's mechanisms and indicating possible design improvements. Part II presented the basic design calculations of the MPM 9 "Bohr" submachine gun.