Introduction. The range of use of composite materials (CM) is constantly expanding, finding application in many areas of mechanical engineering, agricultural technology, aircraft manufacturing, instrumentation, shipbuilding, in the manufacture of high-pressure containers, etc. Quite often, multilayer composites consisting mainly of one type of reinforcing material and a binder are used. Of particular interest is the use of various types of reinforcing materials – more durable in the places of maximum stress in the cross section – in a single composite. As an example, we can use glass and basalt fabrics and fibers using one type of binder. The work objective is to study properties of such a material and to model it using the finite element method.

Materials and Methods. The components used are commercially available. BT-11 basalt fabric, TR-0.5 fiberglass, as well as glass mat with a density of 300 g/m2 were used as reinforcing materials. An epoxy resin of the ED-20 grade with a PEPA hardener was used as a binder. Two types of material were also manufactured for tensile and bending tests, respectively, the differences of which consisted in the number, type and layer sequence. For modeling, CAD COM-PASS 3D, APM-FEM module was used.

Results. Basalt fabric is used in the outer layers of the composite material, fiberglass – in the inner layers. This approach provides increasing the tensile strength of the composite during tensile and bending; however, critical failure leads to an instant loss of the bearing capacity of the material. The use of glass mat as the core of the composite material showed lower allowable stresses, both tensile and bending; but in case of bending, it turned out that when the material was delaminated, the load-bearing capacity of the material was about 10% of the maximum. Modeling of the material is possible with some assumptions, in view of the size of the final elements.

Discussion and Conclusions. The use of basalt fabrics as a reinforcing material provides obtaining products with the properties of both glass and carbon plastics. Such a CM will be slightly more expensive than fiberglass and much cheaper than carbon fiber. Products made of composite materials (equivalent to isotropic materials) can be modeled in computer-aided design systems using the finite element method. It is important to consider the type of loading on the product, since CM mainly have anisotropic properties (the load is applied taking into account the direction of fibers). In multilayer CM from structural fabrics, it is necessary to direct the loads along the fibers. In addition, it is necessary to consider the interlayer shear, different adhesion between the layers, etc. The main assumption of this method is the “constancy” of the material thickness, the number of layers and the order of their location.

Introduction. The influence of two ways of organizing scalar product on the convergence rate of the solution in the energy method of boundary states is considered. The method is based on the spaces of internal and boundary states which are conjugated through isomorphism. Both spaces are orthonormalized using one scalar product or another. The desired state is expanded in the Fourier series according to the elements of the orthonormalized basis; and the coefficients of this linear combination are determined. The two methods differ in the assignment of scalar products and the calculation of the Fourier coefficients.

Materials and Methods. In relation to the method of boundary states, a new theory of organizing a scalar product in the spaces of internal and boundary states is proposed. Computational algorithms are constructed for its practical implementation. In the traditional (first) approach, the internal energy of elastic deformation is used as an orthogonalizer in the space of internal states. Here, the Fourier coefficients are the work of given forces on the basis vectors of displacement of the boundary points. In the studied (second) approach, scalar products are integrals of the cross products of the basis force vectors at the boundary. Accordingly, the Fourier coefficients are calculated as integrals of the product of the given forces at the body boundary by the basic force vectors.

Results. A numerical study of the first primal axisymmetric problem of the elasticity theory for a transversely isotropic cylinder in the absence and presence of mass forces is conducted. In the absence of mass forces, an analysis of the elas-tic fields obtained for the same number of used basic elements has shown that the second method has the greatest accuracy of the results. Under solving the problem with the presence of mass forces, the second method did not show effi-ciency in terms of the uniqueness of the solution; however, it is quite suitable for constructing a multitude of elastic fields used to solve more complex problems.

Discussion and Conclusions. The results obtained can be used to solve boundary-value problems of mechanics of not only an anisotropic body, but also an isotropic one. When solving more complex problems, such as contact and mixed ones, the issue of the rate of convergence requires a separate study.

Introduction. The history of solving the problem of welding structures made of stainless and heat-resistant metals and alloys goes back several decades. Researchers were particularly interested in working with deformed aluminum alloys 2–6 mm thick. As a rule, such thin-walled structures are welded in an argon shielding gas at relatively small currents; therefore, metal transfer is large-droplet (the weld is shaped in the form of separate large droplets with a narrow penetration of the welding components). At the same time, the weld is very convex, which does not meet the operational requirements of the structures. Thus, it was important to solve the following problems: to obtain a controlled fine-drop transfer of electrode metal at currents corresponding to a large-drop transfer; to determine a condition for the controlled transfer; to develop a power supply system for the welding arc.

Materials and Methods. The behavior and parameters of the arc were recorded through the high-speed film and video shooting with synchronous oscillography of the electrical process parameters – current and voltage. They were recorded by light-beam oscilloscopes and two-screen oscilloscopes. The data were processed using a computer complex and Diadem 10.1 software.

Results. The basic condition for the controlled metal transfer is determined through applying current pulses to the welding arc from special pulse sources with and without energy storage devices. Transients in the electrical circuits of the main welding source during the current pulse action and pause are considered. The factors providing stability of rigid and flexible pulsed-arc welding (PAW) are indicated.

Discussion and Conclusions. The results of studying the possibility to control the welding arc processing behavior and the proposed methods for calculating the parameters of the PAW mode became the basis for the development of technology and equipment for the mechanized GMAWP of aluminum alloy assemblies. They are introduced at the enterprises of the aviation industry, shipbuilding. Solutions for stainless and heat-resistant steels and alloys are used at the motor industry enterprises. As a result of studies on the mechanized CO2 activated electrode wire welding, a mechanized PAW technology was developed for units of stainless steel electric furnace bodies, structures of road-building, agricultural machinery and ships.

Introduction. The paper considers simulation of the dynamic processes of the brake rigging of a passenger car under braking on a track section with irregularities. The work objectives include the development of a “rigging brakeblock -wheel working surface” contact module in a full-scale computer model of a passenger car in the “Universal Mechanism” software package; and a computer simulation of the braking operating mode from 50 to 32 km/h considering vertical and horizontal track rail irregularities for determining the mechanism of variation of the longitudinal acceleration of the brakeblock and its angular acceleration. The subject of the study is the force interaction of the elements and dynamic processes in the brake system of passenger cars.

Materials and Methods. A new “rigging brakeblock - wheel working surface” contact module, which provides the de-termination of the longitudinal and angular accelerations of the brake rigging of a passenger car, is proposed to the “Universal Mechanism” software package,. The simulated modeling of the brake rigging system of a passenger car with KVZ-TsNII type II trolleys equipped with shoe brakes is carried out.

Results. A full-scale computer model of a passenger car, which includes the designed contact module “linkage brake pad - wheel working surface”, has been developed in the “Universal Mechanism” software package. The car is present-ed as a system of solids connected by elastic and dissipative elements. Using computer simulation, the operating mode of braking was reproduced under reducing the speed of a passenger car from 50 to 32 km/h considering vertical and horizontal irregularities of a railway track. The simulation result was the laws of change in the longitudinal acceleration of the brakeblock and its angular acceleration under braking in the above speed range. Their spectra of longitudinal an-gular acceleration of the brakeblock were constructed. It was determined that the presence of track irregularities affects the spectral composition of the accelerations. In addition, under the superposition of the bogie-frame pitching and bouncing oscillations, when moving along an uneven track, the rigging block can move up and down the wheel-working surface within a range of up to 50 mm. The simulation functionality of the dynamic processes of the brake system of a passenger car was expanded in the “UM-Loko” software package.

Discussion and Conclusions. The results obtained can be used in the design of new rigging brake systems of passenger cars and modernization of existing ones at the engineering enterprises and railway-car repair works. This, in turn, should ensure uniform distribution of efforts across all brake rigging brakeblocks of a passenger car.

Introduction. Since welding is the only means to connect pipe lengths into a continuous line when constructing main pipelines, modern quality management systems for the welding industry products are based on minimizing the occurrence of specific defects. This is achieved through monitoring and documenting welding procedures.

Materials and Methods. The analysis of monitoring systems customized for manual, mechanized and automatic orbital welding has shown that the industry urgently needs systems that not only control and document the welding process, but also predict the quality of weld joints. This actualizes the need to develop an intelligent module that could, basing on real-time monitoring results, predict the quality of welded joints on the fly.

Results. Since the theoretical connection between the forecasting results and weld quality attributes is characterized by the interaction of a significant number of physical phenomena continuous in time, the results of welding can be described only by a sufficiently complete nonstationary physicomathematical model of the welding process. However, in order to be able to predict the results of welding directly during the monitoring of the process, a simplified forecasting model is proposed whose key feature is the ability to perform calculations synchronously with the real process, which is implemented in a real-time mode with a given interval.

Discussion and Conclusions. The major obstacle to the successful functioning of the operational forecasting module, apart from the length of the numerical solution of equations, is an estimation error. To ensure the minimum error of virtual display during simplification, it is necessary to conduct comprehensive studies of the significance and influence of individual factors and phenomena on quality attributes. These observations determined the content and sequence of work on the creation and implementation of an intelligent module for the operational forecasting of welding quality.

Undoubtedly, the information on the forecasting of the weld joint quality should enter a higher-level pipeline quality management system, as well as be analyzed by construction organizations in order to develop preventive measures to improve the organization and performance of welding work.

Introduction. The study of the austenite magnetic state in steels has provided the mechanism of the external magnetic field impact on steel under the hardening process. Previous studies have established a positive practical effect of heat treatment in a magnetic field. The work objectives were to create a computer model of the magnetic state of carbon steel austenite; to conduct computational experiments with a system of spins at various values of temperature and external magnetic field.

Materials and Methods. The positions of the Ising model were used. The canonical ensemble of spins was modeled by the Monte Carlo method using the Metropolis algorithm.

Results. The algorithm was implemented with the initial parameters selected through experimental data on the magnetic state of austenite. The inhomogeneity of this state without exposure to a magnetic field was studied. Data on the sizes of ferromagnetic clusters in austenite at various temperatures were obtained. It has been noted that the presence of an external magnetic field counteracts the temperature disordering of spins. Data on an increase in the size of ferromagnetic clusters under growing magnetic field strength were obtained.

Discussion and Conclusions. A two-dimensional computer model of the spin state of austenite of carbon steel has been developed. The computational experiments with various parameters of the model have shown that there is a short-range order in the arrangement of spins above the Curie temperature. With a rise of the temperature of the system, the sizes of ordered regions decrease; but when an external magnetic field is applied, they increase.

Introduction. The paper considers analytical studies on the “rotor – gapped-type support” dynamic system under process loading. The research objective is to obtain expressions for determining the equivalent stiffness characteristics of the system.

Materials and Methods. A rotor rotating in the elastic gapped-type supports is considered. A dynamic model that enables to consider the problem of determining the linear equivalent stiffness characteristics of mounting groups is pro-posed. To solve the problem, a system of differential equations is compiled, and a detailed analysis is performed.

Results. From the obtained dynamic equations of the system in question, we can calculate the static angular deviation of the rotor pins due to the action of the load. The proposed expressions for determining equivalent stiffness characteristics testify that it is possible to study the rotor dynamics as on the linear elastic supports with the above parameters. The obtained system of equations is analyzed, and all special cases of applying the first approximation formulas for equiva-lent stiffness of the rotor mounting groups are listed.

Discussion and Conclusions. The results obtained make it possible to study many dynamic processes on the basis of linear differential equations considering the nonlinear properties of the system. For shavers used in the production of leather materials, the determination of rotor vibrations in the horizontal plane provides the quality and accuracy of operations.

Introduction. The paper considers the mathematical analysis of the fractional composition of dust generated during the operation of the rail-cutting machine. It is established that the studied polydisperse material is well described by the one-parameter exponential distribution. At the same time, the lognormal particle size distribution, whose parameters are determined by mathematical programming methods, seems adequate for the purposes of calculating cyclones. The work objective was to develop mathematical methods for correct averaging of the size and mass parameters of dust under the solid metal machining.

Materials and Methods. We studied the possibility of approximating experimental data by Rosin – Rammler distributions (classical, generalized three-parameter P(x, D, n, m), and simplified exponential P(x), in which n = 1). The corresponding results were compared to each other and to the data of approximation of the lognormal and double lognormal functions. These results indicate close approximation quality using the following model distributions P(x):

• five-parameter double lognormal;

• three-parameter type of Rosin-Rammler;

• two-parameter classical Rosin - Rammler;

• one-parameter exponential.

Results. The primary physical analysis of cutting waste was carried out by the laboratory measuring complex Fritsch Analysette 22 Compact which uses the LALLS – low angle laser scattering method. The built-in software provides output of measurement results in primary graphic and digital forms. It was found that the simplest exponential distribution is best suited for a detailed analysis of the dust particle-size distribution based on the experimental data.

This distribution enables reproduction of all the integral indicators provided by the instrumental measuring complex along with the graphical data.

Discussion and Conclusions. The results obtained can be used to rationalize the local suction machine, and the mathematical models and algorithms can be used for the parametric analysis of any dust captured by cyclones.

Introduction. In the algorithm for predicting the resource of machine parts, models of external actions, fracture resistance, and temporal development of a particular type of damage to these units interact. The applied issues of the resistance of machine parts to fatigue failure are considered. The scientific research and regulatory materials are adapted to determine the characteristics of endurance to the specifics of structures and materials of the construction-and-road machinery and agricultural machinery. The work objective is to use the analysis of existing methods to develop recommendations for the calculated determination of the endurance parameters of structural members of the agricultural machines.

Materials and Methods. The initial data were scientific studies on the fracture mechanics of the engineering materials and structures, as well as standards for endurance characterization methods. The need to test methods for determining fatigue characteristics to use them in the road construction machinery and agricultural machinery projects follows from the specifics of their designs, operation conditions and industry-specific range of materials. Based on the analysis of existing methods, it is required to develop recommendations for the calculation of the endurance parameters of structural parts of the agricultural machines. For this, the components of the load-bearing systems of the staged design were presented in the form of a set of plates of the corresponding thickness; and the concept of the critical radius of the stress raiser at the welding sites was also used. Numerical methods using mathematical models were applied. The calculation results were verified through comparing them to experimentally determined fatigue characteristics of the members of a combine harvester on a test bench.

Results. Radius critical values of the stress raisers for various types of welds are obtained. The tables of the calculated and experimental endurance limits of the combine bearing components are well correlated and can be used under designing.

Discussion and Conclusions. The theoretical foundations laid down in the study open up great opportunities for applications to the design of various machines. The considered fragment of adaptation of the theoretical approach to the agricultural engineering objects can be used in the design of load-bearing systems in the related fields of engineering.

Introduction. The structural state of the surface layers of engineering products manufactured through laser processing under various irradiation modes is considered. Structures with the highest possible stability with respect to external action under friction conditions, or with the possibility of optimal adjustment and additional hardening during operation by the formation of secondary structures, were implemented. Under the operating conditions, under the impact of mechanical and thermal pulses, an express rearrangement of one structure to another occurs, which is stable at a higher level of load-speed conditions. Thus, the phenomenon of structural-energy adaptability is realized. The resulting adapt-able structures most efficiently dissipate the energy introduced into the tribosystem, and minimize the wear of friction pairs.

Materials and Methods. We studied samples of P6M5 steel using the following equipment:

• Kvant-16 processing station with a power density of 100 MW/m² for pulsed laser irradiation of samples;

• Neophot-21 optical microscope for metal physical studies;

• DRON-0.5 diffractometer for phase composition identification.

Results. It is established that the material of the samples after laser treatment is able to efficiently dissipate the energy supplied during friction through its transformations at various structural levels. As a result, it becomes possible to control the surface strength and wear resistance of materials using the concept of structural adaptability of friction pairs, which extends their range of performance. Wear resistance of the irradiated steels is determined by both their initial hardness and the work-hardenability during friction. It is established that the thermal-strength loading of the steel sur-face irradiated layers during friction destabilizes austenite to the γ→α transformation, i.e., it contributes to its transformation into deformation martensite.

Discussion and Conclusions. In relation to the specific loading conditions, it is required to regulate the amount and degree of stability of the residual austenite in laser-hardened steels and alloys, which provides the necessary operational properties.

Introduction. The problem of automatic license plate recognition is considered. Its solution has many potential applications from safety to traffic control. The work objective was to develop an intelligent recognition system based on the application of deep learning algorithms, such as convolution neural networks that consider automotive standards for license plates in various countries and continents, and are tolerant to camera locations and quality of input images, as well as to changing lighting, weather conditions, and license plate deformations.

Materials and Methods. An integrated approach for the problem solution based on the application of convolution neural network composition is proposed. An experimental analysis of neural network models trained to meet the requirements of the universal license plate recognition task was conducted. Based on it, models that showed the best ratio of quality and speed were selected. Quality of the system is provided through the optimization of various models with different modifications. In particular, convolution neural networks were trained using images from several datasets. In addition, to obtain the best results, the models used were pre-trained on a specially generated synthetic dataset.

Results. The paper presents numerical experiments, the results of which imply the superiority of the developed algorithm over the commercial OpenALPR package on public datasets. In particular, on the 2017-IWT4S-HDR_LP-dataset, license plate recognition accuracy was 94 percent, and on the Application-Oriented License Plate dataset, 86 percent.

Discussion and Conclusions. The resulting algorithm can be used to automatically detect and recognize license plates. The experiments show that the algorithm quality meets or exceeds quality of the commercial OpenALPR package. The developed algorithm quality can be improved through increasing the training dataset, which does not require the participation of the developer.

Introduction. A mathematical model of the industrial safety monitoring system in mechanical engineering is investigated. The work objective was to create a mathematical model based on expert assessments of workplace safety parameters with a calculated and experimental justification of its applicability to the “STRAZH” expert security monitoring system.

Materials and Methods. The classification of expert systems for engineering enterprises is proposed. The stages of creating expert systems are considered. A methodology for assessing the consistency of experts as a basis for models of expert systems in the field of mechanical facilities safety is presented.

Results. The basic safety parameters of the workplace are identified. A matrix of expert evaluation of parameters based on the opinion of leading experts in the field of engineering is created. The results of modeling the expert system “STRAZH” with the calculated and empirical support of the mathematical model validity are presented. The advantages of implementing expert systems to increase the level of personnel safety are proved.

Discussion and Conclusions. The results obtained have a high degree of expert coordination and can be used in the development of expert safety monitoring systems for engineering enterprises.

Introduction. Fundamentally important problems of the structure mapping and transformation, functions and parameters of various properties in the systems of information knowledge objects organization, as well as functionally different parameters in the management processes of transformations of material objects, are considered. For this purpose, structural-functional-parametric models and parametric models are respectively used. The distinction between these concepts is relevant and practically significant. The scientific novelty of the presented work involves studying methods and information tools used to determine functionally different technological schemes for the interaction of objects at the stages of design and pre-processing engineering.

Materials and Methods. The concept of a “structural-functional-parametric model” is associated with the definition of the structure of the basic knowledge objects of the subject area. In this case, the “linking base” is the methods and corresponding means of system engineering in the infological modeling technology that are used to solve practical problems. The concept of a “parametric model” is associated with the solution to practical problems of the process control.

Nature of these tasks is functionally different (technical, physical, chemical, biological). It should also be clarified that, in this case, we are talking about converting the parameters of various properties of real objects by methods and means of system engineering (almost a mathematical apparatus).

Results. A “structural-functional-parametric model” and a “parametric model” are general theoretical concepts that have invariant properties necessary for solving practical problems of the subject knowledge area. Considering the organization system and management processes in this way, note that it is required to maintain data and logical connections be-tween them under static and dynamic settings.

Discussion and Conclusions. To solve practical problems in the subject knowledge area according to the technology of information logical modeling, certain methods, tools, algorithms, and operations are used. The most complete mapping and transformation of information objects is possible only in structural-functional-parametric models and databases of their solutions. The application of structural-functional-parametric models is the most important condition for a success-ful transition to a high-level deterministic automation of information technology for solving practical problems of the subject area. As an example of such a problem, we can cite the machining production design engineering.