Fused deposition modelling, alternatively referred to as Fused Filament Fabrication, is an additive manufacturing technique that has garnered significant attention across various industries due to its diverse applications. This research investigates the ultimate tensile strength and elastic modulus of 3D-printed Polylactic acid samples, following the ISO-527-2-2012 standard. The mechanical performance of the created parts is considered from both experimental and computational points of view. The finite element method within the ANSYS environment was employed for computer-based load and strength calculations. Tensile specimens are fabricated using the Fused deposition modelling approach. The experimental outcomes were utilised to derive all the essential engineering constants required for evaluating the mechanical behaviour. The validity of the theoretical model has been confirmed through a comprehensive comparison with a substantial volume of experimental data, exhibiting mean errors of approximately 1%. The objective of this research is to assess the effectiveness and efficacy of analytical models in predicting the structural and mechanical behaviour of components produced through fused deposition modelling.

https://doi.org/10.48081/MFBQ8991

2023

Issue 3

In this work, the influence of technological factors and the macrostructure of hollow cast billets made of 25CrV steel on the mechanical properties at various temperatures was studied. It has been established that the branched transcrystalline macrostructure of pipe billets is the most favorable. The temperature parameters of continuous casting are determined, which ensure the production of a branched transcrystalline macrostructure of pipe hollow billets. A comparative analysis of the mechanical properties of pipe billets obtained at different temperatures of casting the melt, which have a transcrystalline (columnar) macrostructure, is carried out, and with an increase in the degree of its dispersion, the strength and plastic properties increase. It is shown that the presence of a large temperature gradient promotes the formation of columnar crystals, the orientation of which is determined by the direction of the heat flow. To ensure high mechanical properties, it is necessary to obtain a finely branched transcrystalline macrostructure of the billets.

https://doi.org/10.48081/PRBW4597

2023

Issue 3

The article presents the results of the research work within the framework of the state-funded research AP09258862 "Development and research of a multipurpose vehicle". The necessity of increasing the efficiency of the use of transport equipment is described. One of the ways to improve the performance of machines is to improve the running system of traction vehicles. The longitudinal and transverse stability of the traction vehicle is also important. The object of the study is a semi-tracked propulsion, which is a combination of wheeled and tracked propulsion. Based on the analysis of the existing designs of semi-tracked propellers, the research team has developed a new design of a semi-tracked propulsion traction vehicle. The description of the mover is given. The stability of traction vehicles is characterized by their ability to work on longitudinal and transverse slopes without overturning. The main criteria for the stability of a traction and transport vehicle against overturning are the characteristics of its geometric parameters and the location of the center of mass relative to the mover, which determine the boundaries of static stability using the so-called limit angles. The article offers expressions for determining the limiting angle of longitudinal stability of a semi-tracked traction and transport vehicle. The authors selected tractor Belarus 82.1 as the base of the investigated semi-tracked traction and transport machine. As a result of calculations, the maximum lifting angle was 〖 α〗_n = 56°.

https://doi.org/10.48081/JRMW8460

2023

Issue 3

Currently, there is a wide variety of metal-cutting tools. The nomenclature of the cutting tool is determined based on the analysis of shapes, sizes, required accuracy and roughness of the main and additional surfaces of the parts, taking into account the type of the selected workpiece. The use of lubricating and cooling technological means (LCTM) has an efficient effect on increasing the durability and wear resistance of tools, also in metalworking. The physico-chemical mechanism of action of the LCTM is rather complicated complex and is mainly due to a change in the conditions of interaction of the surfaces of the cutting wedge of the tool with the material being processed, which is expressed, first of all, in a change in the contact conditions. Based on the analysis of the designs of domestic and foreign manufacturers of metal-cutting tools, it is concluded that the development of new designs is carried out in the direction of designing assembly structures, replaceable cutting plates, as well as using combined cutting tools. The design features of the incisive assembly reamer and the quality of the working surfaces of the cutting wedge of the teeth ensure high efficiency of the finishing operation of the reaming increased processing accuracy, as well as tool durability and reduced roughness of the machined parts. Experimental studies of the processing of holes of a incisive assembly reamer based on the planning methodology have shown that the quality of processing holes with a incisive assembly reamer with a rigid attachment of the topless teeth when using coolant increases by 1.2..1.3 times with the use of LCTM, due to a decrease in temperature and friction in the cutting zone.

https://doi.org/10.48081/APHA8929

2023

Issue 3

This article presents the results of a study of the state of the problem of processing hard-to-process materials in the conditions of domestic and foreign machine-building industries. It is revealed that the processing of hard-to-process materials by cutting is a problem that is accompanied by material costs and low productivity. The problem may also lie in the high consumption of cutting tools, since these materials have high hardness, strength, viscosity, corrosion resistance, heat resistance with low thermal conductivity, which makes it difficult to process cutting. A method of mechanical processing of hard-to-process materials by high-speed milling is proposed, which is currently one of the developing directions and insufficiently studied in comparison with other methods. However, it has been revealed that when using high-speed milling, there is a problem of choosing cutting modes depending on the material being processed and the material of the cutting tool. There is also no reference data on the choice of cutting modes for processing at high speeds. Since previously used universal machines were not able to provide more than 2000 rpm, and accordingly, recommendations are given in the reference books according to these values. The results of experimental studies of the process of high-speed milling of high-strength alloy steel 30HGSA are presented. The results obtained showed that there are high resources of this method. With correctly selected cutting modes, it is possible to achieve high quality machining indicators and increase productivity.

https://doi.org/10.48081/QLOD6747

2023

Issue 3

This article presents the phase transitions of a nickel-containing alloy and the composition of a complex alloy. A four-component Ni-Fe-C-O system was created and the results of a mathematical model for calculating the phase composition of a nickel-containing alloy were determined. It was found that the four-component metal system Ni - Fe - C - O consists of four separate metal three-component systems Fe - C - O, Ni - C - O, Ni - Fe - O, Ni - Fe - C, and when analyzing the phase equilibrium of compounds of the quaternary system Ni - Fe - C - O, the considered four - component system consists of 14 tetrahedra and is calculated by the Hiza method of the entire volume . The breakdown of the general system is carried out taking into account congruent and incongruent compounds. The sum of the relative volumes of elementary tetrahedra is equal to (V=0.999989), which confirms the correctness of the tetrahedron. It was proved that when the elements in the composition of a nickel-containing alloy change, i.e. Ni - 15-45%; Fe 54.0 - 82.5%; C 1.0 - 2.5%, the phase composition of the alloy is in the Fe - Fe3C - Ni3Fe region.

https://doi.org/10.48081/XNZI9820

2023

Issue 3

One of the most important and difficult problems related to the grinding process in a stirred mill is the high energy intensity. This article proposes a method for reducing the energy intensity of the grinding process in a stirred mill. The essence of this method bases on the organization of the radial and axial impact on the particles of the grounded material. This is achieved by the use of a new stirred mill design. While the radial action is conducted by the rotation of the ellipsoidal stirrer, the axial one is conducted by the vibrational oscillations of the chamber. The dependence of the theoretical power on the functioning parameters of the new grinder was established, and a computational experiment was carried out on the basis of this. As the investigation results showed it is possible to reduce energy consumption in a stirred mill by 20 % as a result of the use of this method.

https://doi.org/10.48081/GOJT6832

2023

Issue 3

Designing road traffic noise protection presupposes developing noise protection measures with due account to road traffic characteristics, technical specifications of roads, natural environment as well as to the real acoustic contamination and characteristics of a dwellings zone. Basis of noise protection is developed for a twenty-year period at the design stage; therefore, providing acoustic safety is a significant task. The article considers the problem of designing a reconstructed road section with a two-level interchange. An example of work according to the technical assignment for designing noise protection for a reconstructed road section with uninterrupted traffic with a two-level interchange is described. Acoustic calculations for road elements with various vehicle densities were performed. Design points in dwellings zone were defined; the required reduction of equivalent sound levels was calculated to achieve the acoustic standards. These calculations allowed designing protective structures, acoustical shields, which were a design solution. Similarly, additional acoustic calculations for the elements of a street and road network such as reconstructed road exits and the main artery with regulated traffic that is located under the interchange were performed. These elements belong to the project construction site but they are not included into the technical assignment. It was found that to comply with the acoustic standards in a dwellings zone, it is necessary to calculate acoustic impacts of all the elements of the designed street and road network section but not only the elements of the reconstructed road section as is usually specified in a technical design assignment.

https://doi.org/10.48081/OQFJ9498

2023

Issue 2

Reasons for the destruction of nodes and parts of wind power plants are analyzed, taking into account the peculiarities climate in the Republic of Kazakhstan. It is established that the most worn-out unit is a multiplier reducer, which is subjected to static and dynamic loads during operation. Exceeding the maximum permissible loads in real conditions can lead to a breakdown of the wind power plant. Endoscopy method was used to determine the condition and degree of wear of parts and assemblies of wind power plant. As a result of study, gearbox parts destroyed and damaged as a result of critical wear are: cylindrical stage housing at junction of cylindrical stage housing and gear ring of second stage (a crack measuring half circumference) and elements of gears. Defect cause in form of a crack on cylindrical stage housing at junction of cylindrical stage housing and second stage gear ring with a size of half circumference may be alternating loads on gearbox housing from gear gears, due to ingress of chipped teeth and chips when teeth are painted into gear engagement. The defect in form of discoloration of gear ring teeth, planetary and solar gear, furrows on teeth arose as a result of action of repeatedly variable contact stresses, which contribute to formation of microcracks on surface of teeth, further development of cracks contributes to wedging effect of lubricant trapped in cracks of teeth and material particles from the surface.

https://doi.org/10.48081/OBEO6342

2023

Issue 2

The article presents the technological calculation and selection of a shell-and-tube heat exchanger in the Mathcad package. Of all types of heat exchangers used in industry, about 80% are shell-and-tube heat exchangers. For the calculation of heat exchangers, spreadsheets (Excel) are most often used. The disadvantage of such calculations is the beloved record of formulas and the equanimity to plot the resulting Bindings. Recently, programming in the MatLab package has been increasingly used, but even here there is no impudence in recording the format. When programming in the Mathcad package, the format is recorded in a generally accepted form, which allows you to immediately see inaccuracies in their recording and make appropriate changes. The audacity of writing formulas is the main advantage of Mathcad over other calculation programs. Based on the developed program, thermal and aerodynamic calculations of heat exchangers were released, which made it possible to compare heat exchangers and choose the best option for the reserve area of heat exchangers and prescription losses. This program can be used both in the educational process when writing diplomas and master's theses, and in design organizations when designing shell-and-tube heat exchangers.

https://doi.org/10.48081/QHHO9235

2023

Issue 2