The object of this study is the processes of occurrence, exposure to, and redistribution of loads in the supporting structure of a removable module for the transportation of long cargoes. To adapt platform cars to the transportation of long loads, it is proposed to introduce a removable module with elastic-friction connections in the structure. In order to select the optimal profiles for the removable module, in terms of minimal material consumption, the calculation was carried out in the Lira software package. Based on the calculation results, a spatial model of the concept of the removable module was built. To determine the dynamic loads that act on the platform car loaded with a removable module, a mathematical simulation was carried out. It was established that the use of elastic-friction links in the structure of the removable module helps reduce its dynamic load, as well as the platform car, by 4.6 %. The resulting acceleration was taken into account when calculating the strength of the removable module. The calculation results showed that the strength of the removable module under operational loads is ensured. A feature of the reported results is that the proposed design of a removable module makes it possible not only to adapt the platform car to the transportation of long loads but also to reduce its load in operation. The scope of practical application of the results includes the engineering industry, in particular, railroad transport. Worth noting is that the conditions for the practical use of the results imply the introduction of elastic-friction links in the structure of the removable module. The reported research will contribute to compiling recommendations for the design of modern vehicle structures, in particular removable type, as well as for improving the efficiency of rail transportation.

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, v_c = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of v_c = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.

Fabrication of alumina–tungsten carbide nanocomposite was investigated. Characteristics of the densification and sintering were analyzed considering both the nano-size particle starting powders and the processing stages. Different heating rates were generated during densification and consolidation with a maximal load was applied only after a temperature of 1000 °C was reached. Due to the varying dominance of different physical processes affecting the grains, appropriate heating rates and pressure at different stages ensured that a structure with submicron grains was obtained. With directly applied alternating current, it was found that the proportion Al₂O₃ (50 wt.%)–WC provided the highest fracture toughness, and a sintering temperature above 1600 °C was found to be disadvantageous. High heating rates and a short sintering time enabled the process to be completed in 12 min, saving energy and time.

This article is devoted to the analysis of mathematical models of the charge-discharge characteristics of lithium-ion batteries. A review of existing equivalent circuits and mathematical models of lithium-ion batteries is presented. The discharge characteristics of a real NCR-18650b battery were obtained during discharge with current value (0.2C, 1C, and 2C). The results of a study of the thermal regime of the battery are presented, which show the battery overheating above the permissible value. The structure and mathematical model of the Battery library block in Matlab Simulink are described. The simulation of the NCR18650b battery discharge process in the Matlab package was performed at the same discharge currents. The results showed that the discharge characteristics presented in the technical documentation for the NCR-18650b lithium-ion battery differ from the characteristics obtained as a result of a physical experiment on a real sample and the characteristics described in the standard mathematical model of the battery in Matlab. A comparative analysis of the relative error in the simulation of discharge processes in three intervals of the discharge characteristic is presented. Recommendations on improving the accuracy of modeling are given.