Search

The article discusses methods for solving a system of linear algebraic equations. The advantages and disadvantages of various methods for solving the contact problem are presented. The method of upper relaxation is given as the most optimal from the viewpoint of applying in CAE systems. [ABSTRACT FROM AUTHOR]

Studies of fatigue crack growth in steel 2CR31 without coating and steel 2CR31 with coating NI-CR-B-SI have been carried out. The works of V.E. Panov are analyzed. On the basis of his works, studies of fatigue cracks are presented. It is shown that the process of fatigue fracture of a steel sample is accompanied by a regular decrease in the natural frequency of all recorded modes. [ABSTRACT FROM AUTHOR]

This work solves the problem of assessing additional accelerations arising from temperature shock when a small spacecraft comes out of the Earth's shadow and immerses into it, in order to make recommendations for the accelerations level control in the area of technological equipment intended for the realization of gravity-sensitive technological processes on board small spacecraft. [ABSTRACT FROM AUTHOR]

The article provides an example of controlling the stress state parameters of additively obtained products. The study is based on the developed non-classical mechanical model of the process of layer-by-layer formation of a coating of arbitrary thickness on a cylindrical substrate. The model is based on current representations in mechanics of continuously growing solids and allows us to obtain fairly simple analytical dependencies. Based on the latter, the paper solves a problem on the technological control of the contact pressure evolution at the substrate–coating interface. A number of practically significant conclusions are made. [ABSTRACT FROM AUTHOR]

In the course of the researches carried out, it was theoretically proved and experimentally confirmed that the elastic-hysteresis properties of elastomers determine the trajectory of particle motion upon impact on their surface, the magnitude of the velocity loss and the angle of rebound. The presence of three zones of angles of attack was experimentally established, up to approximately 30°, from 30° to 60° and over 60°. Depending on the elastic- hysteresis properties of elastomers, the effect of these properties on the value of the rebound angle and the loss of speed is inverted. [ABSTRACT FROM AUTHOR]

This work is devoted to the formulation and construction of an analytical solution for the problem of contact between a cylindrical viscoelastic aging pipe with an internal thin coating and an insert with a complex shape placed inside the pipe with an interference fit. In practice, the presence of such a coatings is required, for example, for protection of the main construction from aggressive external or internal media, for its electrical insulation, etc. Due to manufacturing processes, this internal coating may be nonuniform (its properties depend on coordinates). An insert placed inside a pipe can have a complex profile described by a rapidly changing function. Taking into account such a features is important when analyzing the stress-strain state of pipe with internal coating. Using an approach based on the use of special basis functions and the form of a solution, a representation for the contact stresses in a pipe in the region of a rigid insert is obtained. It allow one to single out the functions describing the properties of the inner coating and the shape of the outer profile of the insert in the form of individual terms and factors in the expression for the contact stresses in the region of the insert. Therefore, it will be sufficient to restrict ourselves to a relatively small number of terms in the series to achieve high accuracy in calculations. [ABSTRACT FROM AUTHOR]

Mechanisms that convert rotational motion into reciprocating or oscillating motion are widespread in the machinery. Most often they are used in combination with gearing. Both of these functions are capable of performing one mechanism - an eccentric bearing. The article considers the task of studying kinematic capabilities and rational parametric relations of various modifications of gear eccentric system (GES). [ABSTRACT FROM AUTHOR]

Wheeled tractors and wheeled earth-moving machines are widely used in road construction, in municipal services. The group of wheeled vehicles, numerous and varied in purpose and design, are general transport vehicles used for the transportation of various types of bulk cargo, and specialized vehicles designed to perform narrow target functions. A characteristic feature of these types of wheeled vehicles is their ability to work not only on roads with asphalt-concrete pavement, but also on deformable soil surfaces. When the wheels roll on the ground, the power consumption required to ensure the movement of the wheeled vehicle increases sharply, questions arise related to the passability of the vehicles, their controllability, and the loads in the transmission. In this regard, it becomes necessary to consider various aspects of the movement of machines in these conditions, in particular, the determination of the power spent on rutting and the depth of the track, which is what this study is devoted to. The use of the "stamp wheel" model in this work made it possible to obtain relatively simple dependencies that make it possible to calculate the depth of the track and the power spent on rolling both a single wheel on deformable soil, and during sequential passage of wheels with a widening of the track, when the next wheel does not move "in trail", i.e. exactly along the track laid by the first wheel, and with some lateral displacement. In this case, part of the wheel moves along the laid track, and the other part expands the track, compacting the previously non-deformable soil. The results of calculations using the derived formulas are in good agreement with experimental data, which indicates the practical applicability of the obtained dependences. [ABSTRACT FROM AUTHOR]

The paper describes the features of the electrochemical formation of a modern abrasive a diamond-bearing composite material with a ceramic matrix based on aluminum oxide and investigation on its tribological properties. The technology for forming an abrasive superhard material involves the electrochemical conversion of an aluminum binder into a corundum matrix using microarc oxidation of the surface of parts obtained by powder metallurgy from aluminum powder and dispersed diamond of various fractions. The authors applied the technology of chemical metallization with copper in order to protect the diamond surface from oxidation and to increase its mechanical strength. The try-outs of the modes for producing diamond-bearing composite material samples, and comparative tribological tests were conducted on the specially designed equipment. There are the identified factors that determine the features of the technology of diamond-bearing composite material electrochemical formation on various bulk density workpieces, as well as workpieces with a varying percentage composition of material components. It has been established that the diamond metallization degree significantly affects the oxidation process. It is almost impossible to produce composite ceramic material by microarc oxidation with diamonds coated with nanodispersed copper with a metallization degree of over 100%. A change in the material diamond concentration does not affect the creation of stable spark discharges that form the α-modification aluminum oxide. Therefore, the choice of diamond concentration, as well as its grit size, can be based on the required tribological properties of a tool material and the physical and mechanical properties of a part to be processed, and its surface roughness. The relative density of a diamond-bearing composite material sintered blank for microarc oxidation should be 80–90%. In this case, the formed material has optimal physicomechanical and tribotechnical properties. The optimal alkali concentration in the electrolyte for the maximum diamond-bearing composite material thickness is about 2 g/l. The comparative tribotechnical tests have confirmed the advantages of diamond-bearing ceramic material compared with traditional analogues. It has been established that, when processing 16 GPa hardness ceramics, the relative diamond consumption of a ceramic matrix material is 3.3 and 6 times lower than that of materials with a metal and organic bond, respectively. Unlike traditional materials, the volumetric cutting ability of an abrasive tool made of new material initially exceeds this characteristic for metal bond circles by 1.6 times, for organic bond circles by 3.6 times and almost does not decrease during processing. The new synthesized abrasive material will be in demand for producing abrasive tools for high-performance precision microprocessing of superhard materials in various sectors of the precision industry, instrument making, jewelry and watch industry. [ABSTRACT FROM AUTHOR]

The article proposes a model of the friction surface wear of pumping equipment involved in pumping oil and oil products at high temperatures. The applicability of the proposed dependencies is substantiated only for the period of steady-state wear. The general dependences of determining the wear of the surface nanogeometry in the stated mode and their constituent factors are presented. The analysis of the proposed provisions shows that the wear of nanogeometry depends to a greater extent on the deformation and adhesive components. The materials of the article can be used to determine the friction unit wear of oil pipeline pumping equipment, subject to elastic and plastic deformations. [ABSTRACT FROM AUTHOR]

Using optical microscopy, evaluation of the ohmic resistance of oil layers in tribocontact, and tribological studies, the results of the influence of the particle size of soft rocks of the serpentine group: antihorites, lizardites, and chrysotiles on the anti - wear properties of liquid lubricants-LUKOIL Standard 10W40 mineral oil and synthetic Castrol SLX 5W40. The optimal size of serpentine particles is 3...5 microns. The inefficiency of serpentine modification of Castrol SLX 5w40 synthetic oil is proved based on the results of wear intensity testing and measurement of the ohmic resistance of the oil layer in tribocontact. [ABSTRACT FROM AUTHOR]

The use of the technology of combined electromechanical processing, consisting of the high-temperature plastic deformation mode, when the tungsten carbide powder is implanted into the surface of carbon steel, and the high-temperature thermal hardening mode, during which tungsten carbides are partially dissolved in the austenite of the steel up to the limit of its saturation with tungsten, provided a gradient wear-resistant three-layer highly dispersed structure as a result of the decomposition of supercooled austenite oversaturated with tungsten. The results of tribotechnical tests of cylindrical specimens by the normalized method are presented. [ABSTRACT FROM AUTHOR]

A simplified method for assessing the loading of the load-bearing systems of passenger cars with thermal loading by a combustion spot with limited properties has been developed. A system of simplifications for realizing a combustion spot is substantiated. A method for its implementation is proposed. The description of the research object is given with the necessary thoroughness of presentation. A finite element scheme was developed and adapted taking into account the application of thermal loads in the system of the industrial software complex FEM. Verification of the finite element scheme was carried out taking into account full-scale normative experiments. A conclusion about the possibility of applicability of the FE scheme for the study is made. Numerical experiments were carried out to assess the carrying capacity of the body of a double-deck passenger car when it is exposed to a combustion center with known thermal parameters. The experiments were built and performed in a finite element method system. The results of simulations in the affected zone of the alleged fire were obtained for the conditional spot of its placement. Comparison of the results with the mode of static loading of the car body is considered. The analysis of the obtained results is carried out. A conclusion on the effect of a small localization fire on the carrying capacity of the car body is given. The proposed method is evaluated taking into account the possibility of further use. [ABSTRACT FROM AUTHOR]

The paper considers an approach to predicting the risks of emergency situations in transport and improving its safety. The authors show that the forecasting of risks in railway transport is determined by the processes of deformation and destruction at dangerous points in highly loaded zones of critical elements of transport objects. Managing the degradation of transport facilities by using diagnostic systems and innovative technologies at all stages of the life cycle ensures that it is safer and more secure from emergencies. [ABSTRACT FROM AUTHOR]

The model of contact interaction of rough surfaces is considered. Greenwood and Williamson, Amiya Bhushan and Majumdar models are analyzed. Dependences of contact interaction parameters are obtained based on the proposed fractal model. Examples of estimation of contact parameters for nominally flat rough surfaces are given. [ABSTRACT FROM AUTHOR]

The article deals with the material wear of the car wheel flange when the train enters the curved section of the track. Some types of additives are presented and tested for wear in laboratory conditions. It has been found that using certain types of additives reduces wear of the rail-flange friction pair. Releasing diffusion-active hydrogen from the friction zone is shown. The results obtained allow us to assert that additives based on sulfo compounds contribute to decreasing the wear of the flange friction surface and lead to decreasing the release of diffusion-active hydrogen from the friction zone. [ABSTRACT FROM AUTHOR]

The article deals with maximization of diesel cylinder face endurance by development of technology to provide specified accuracy of cylinder face sizes and geometrical shape as well as surface roughness parameters in compliance with Abbot's diagram specified. The issue is complicated by nonuniform structure of metal casting and intricate geometric shape of cylinder cast surface cooling ribs which results in variable stiffness and instability of elastic deformations during cylinder machining. The problem is solved by optimization of technological process structure and replacement with a new, more precise and stiff equipment. [ABSTRACT FROM AUTHOR]

The article considers diamond-abrasive grinding of silicon carbide plates as a tribological system in order to increase the productivity and quality of this processing, as well as to substantiate the directions of its improvement. The process of removing material from the workpiece is considered as a result of abrasive wear of the silicon carbide plate on the lap with free abrasive particles. Based on the hypothesis of F. Preston, a dependence was obtained for calculating the rate of removal of material removed during machining from the surface of the workpiece. The results of experimental studies of the productivity and quality of machining are presented. Attention is paid to the formation of surface layers of silicon carbide plates by introducing abrasive particles into the workpiece, which cause the formation of multidirectional microcracks and the removal of material mainly as a result of brittle fracture. The results of experimental studies of the state of surface layers using a digital 3-D microscope VHX-1000E, a Jeol JSM 6610 scanning electron microscope and a profiler-profilometer "Mahr GmbH" are presented. Based on the research results, recommendations are formulated for improving the efficiency of diamond-abrasive machining of silicon carbide plates. [ABSTRACT FROM AUTHOR]

The article proposes a model of temperature during drilling and an automatic control system for the drilling machine, which allows maintaining the optimum temperature. [ABSTRACT FROM AUTHOR]

We present an analytical solution for the determination of the optimal law of the angular motion of a rigid body in the general case (with arbitrary boundary conditions at the angular positions, on the angular velocity, and the acceleration). We have found the way to programmatically control a solid turning using the formula for moving the point. The formula is based on a quintic vector polynomial in a geometric model of rotational motions as a sphere with radius Pi of a Euclidian space. Two methods for finding the optimal trajectory in the ball are presented. The first method allows you to accurately construct the optimal law of rotation of a solid body, its main difficulty is the calculation of cumbersome expressions. The second method, which does not have this drawback, allows you to find the optimal method using an iterative procedure. A numerical experiment was carried out on a specific example, and the results of the experiments are presented in the form of graphs. The graphs show that the exact solution and the solution obtained iteratively overlap after the second iteration. This result confirms the effectiveness of the proposed iterative method. [ABSTRACT FROM AUTHOR]

The article is devoted to numerical investigation of non-isothermal flow processes of polyethylene-modified polypropylene in the cable head forming tool channels upon application of a two-layer insulation. The influence of technological parameters on the velocity and temperature fields is determined. [ABSTRACT FROM AUTHOR]

The article deals with problem of contact interaction between the diamond grinding tool and the surface of the part. As a result of the research, we have obtained actual areas of contact for the cases of elastic contact, plastic contact and elastic-plastic contact. These areas take into account the sum of actual contact zones of touching bodies, which transmit the force of pressing of grinding wheel to the machined surface. Obtained analytical dependences for calculation of geometric parameters of a contact of diamond face tool with the machined surface of a part allow description, prediction and controlling force and resistance properties of the process according to machining conditions. [ABSTRACT FROM AUTHOR]

The article is devoted to solving the problems of the production of thin-walled cases, where it is important to improve the accuracy of manufacturing. Based on the foregoing, it was decided to conduct research work. The technology of processing a long body from a hot-rolled thick-walled pipe with the use of stretching is considered, which guarantees the required shape accuracy and the least effect of the properties of the initial state of the workpiece in comparison with the technology of manufacturing bodies by stamping from sheet metal. As a result of the work, it was determined that the difference in the diameter of the housing bore when based on the pulling operation is mirrored onto the accuracy of the inner surface of the housing, and the maximum beating of the housing stem obeys the Rayleigh distribution law and fits into the tolerance with a two-fold margin. Experimental studies have shown that an increase in the accuracy of manufacturing extended bodies can be guaranteed by reducing the technological tolerance for the inner base hole of the workpiece for pulling. [ABSTRACT FROM AUTHOR]

The work is devoted to the actual problem of improving the quality and productivity of electronic devices. Increasing the yield when creating equipment containing samples of metallized quartz will increase the efficiency and profitability of piezoelectric resonators produced in this industry. The article describes an improved installation for applying a thin metal foil to quartz resonators. Analysis of the dependence of the measurement accuracy of the film thickness on the type of electrodes, as well as the homogeneity of thin metal films on the distance of the evaporator from the substrate, made it possible to develop recommendations for choosing the most advantageous parameters for the processes of using this device. As a result, it was possible to achieve an increase in the number of useful products. [ABSTRACT FROM AUTHOR]

The article is devoted to the analysis of known structures of impact devices used in industry in order to obtain recommendations for their adaptation or when creating new structures for wave strain hardening by surface plastic deformation. The analysis was carried out on the used drive and on the main parameters of impact devices: impact energy, impact frequency, relative metal consumption and efficiency. The options for the best combinations of parameters for electric, pneumatic and hydraulic drives were established. Recommendations on the use of such devices, with appropriate adaptation, as pulse generators for wave strain hardening were given. [ABSTRACT FROM AUTHOR]

The article provides a review of the reasons for stress corrosion cracking of petroleum pipeline system, terms of reference of fatigue wear and fracture performance caused by both metal fatigue and fatigue wealth. It is shown that stress corrosion cracking can be associated with fatigue of the pipeline material in the presence of local turbulent flows. [ABSTRACT FROM AUTHOR]

The article considers building a computer model of a freight car movement along a track section adjacent to a rail joint. The model takes into account the elastic characteristics and ballast subsidence in the joint zone. The results of computer modelling are further used to solve the contact problem in the wheel-rail system. A varied number of parameters influencing the process of wheel movement are used in the study. For the operating speeds of the freight car movement the value range of the dynamic forces arising between the wheel and the rail while passing the joint are determined. [ABSTRACT FROM AUTHOR]

Wheeled vehicles belong to the most common type of transport and technological machines and are used in almost all sectors of the national economy: in urban and intrafactory transport, in construction, in the army, in agriculture, etc. Due to the fact that wheeled vehicles must correspond to the solution of the tasks that this or that industry poses for them, their structure and types are very diverse. Among them are wheeled vehicles designed to work not only on roads with asphalt-concrete pavement, but also on deformable soil surfaces. These include, in particular, machines used in road construction, in municipal services - wheeled tractors, wheeled earth-moving machines, general transport vehicles used for the transportation of various types of bulk cargo, and specialized, designed to perform narrow target functions. The performance indicators of wheeled vehicles are largely determined by the interaction of their wheels with the supporting surface, which has led to a large number of studies in this area. The rolling of a wheel on a hard surface has been studied in sufficient detail and is presented in a large number of works. At the same time, issues related to wheel rolling on deformable soil have not been sufficiently worked out, there are many uncertainties and inaccuracies. This applies, in particular, to the case of a wheel rolling on the ground with a pull, when the plane of rotation of the wheel is deflected by a certain angle from the vector of the wheel axis velocity, which leads to the appearance of an additional lateral force acting on the tire sidewall and the corresponding moment of resistance to turning. When a wheel with a pneumatic high-pressure tire rolls, the wheel rolls on the ground, almost without changing its cylindrical shape, i.e. practically without deformation. This greatly simplifies the calculations associated with the analysis of the operation of wheeled vehicles. In this article, when considering the rolling of a wheel with withdrawal on deformable soil, the dependences were used to determine the longitudinal and transverse tangential stresses in contact, obtained for the case of wheel rolling on a solid base; the lateral force acting on the tire sidewall and the corresponding moment of resistance to turning are determined. [ABSTRACT FROM AUTHOR]

The deviation in measurements by a rotational viscometer with an elastic element was considered, which arises as a result of friction in the bearings of the measuring part. The results of determining the error arising due to friction torques in the bearings using ball bearings are presented. Methods of mathematical calculation of the error from friction for some bearing structures are presented. A promising design of the bearings of the measuring part of the rotational viscometer is proposed, which allows reducing the error from friction. The results of the experimental determination of the error from friction in the bearings of the proposed design are presented, confirming the effectiveness of using this design. [ABSTRACT FROM AUTHOR]

A method for strengthening conical reinforced concrete posts by external reinforcement with composite materials is considered. There is calculation of reinforced concrete posts according to the limit states of the first group, reinforced with composite materials in compliance with the requirements of SP 63.13330.2012 and SP 164.1325800.2014. Based on the calculation, a comparative analysis of the characteristics of polymer composite materials presented on the domestic market is performed, and rational schemes for external reinforcement of conical reinforced concrete posts used as AMS for installing cellular antenna-feeder equipment are proposed. The results of the analysis can be used for selection of polymer composite materials and schemes for strengthening conical reinforced concrete posts. [ABSTRACT FROM AUTHOR]

This research is of a direct applied nature and is aimed at solving the problem that arose at JSC "Peterburgsky Traktotny Zavod " (hereinafter referred to as JSC "PTZ"). The task was set to theoretically determine the dynamic load of the Kirovets K-4 tractor transmission, in order to exclude the possibility of incorrect design layout of the tractor transmission, in consequence of which, there could be a destruction of the driveshaft between the internal combustion engine and the transmission. The study was conducted on a three-mass mathematical model. The mathematical description is in the form of Lagrange equations of the second kind. [ABSTRACT FROM AUTHOR]

The paper considers a technique for analyzing strength and buoyancy of block pontoons in vertical cylindrical tanks used for storing liquid petroleum products. A model for finite element calculations of a pontoon for buoyancy and strength is proposed, taking into account the buoyancy forces. The calculation results for strength and buoyancy of an aluminum pontoon with foam-urethane filling BPA5000 are presented. It is found that BPA5000 pontoons have sufficient strength and buoyancy, regulated by All-Union State Standard (GOST) 31385-2016. [ABSTRACT FROM AUTHOR]

Toothed-lever and cam-toothed-lever mechanisms are widely used in technological equipment of automatic and semi-automatic action to convert the one-way rotational motion of the input link into a one-way rotary motion of the output link with periodic stops. To ensure periodic rotation with a precise fixed length, an elastic element with a double-sided preload is introduced into the mechanism, as a result of which the mechanism has a variable structure. Compared to other intermittent turning mechanisms, in toothed linkage mechanisms there is a wide possibility of influencing the function of the position of the output link, the angle of reverse rotation and the relative displacements of the links connected to each other by an elastic element by changing the lengths of the links of the basic four-bar linkage. [ABSTRACT FROM AUTHOR]

Isotropic parallel manipulators are considered. The structure and kinematics of the parallel translational manipulator guide Pantopteron are analyzed. It is established that Pantopteron mechanism, which includes pantographs in the kinematic chain to increase the speed, contains redundant connections and is statically indeterminate. Structural schemes of statically definable parallel Pantopteron manipulators are developed and proposed. [ABSTRACT FROM AUTHOR]

The analysis of the design features of the trolley of the shunting diesel locomotive TEM23. In the process of this analysis the directions for its improvement are determined. It is proposed to ensure the rotation of the trolley frame in the vertical plane by reducing the body supports to two and to use a low-lowered kingpin, to equip the trolleys with pneumatic spring suspension in the form of two-corrugated shells installed in series with shortened spring suspension springs. The proposed options for improving the diesel locomotive undercarriage will increase the competitiveness of products and reduce costs. [ABSTRACT FROM AUTHOR]

The problem of the possibility of creating a classification of methods for fastening traction electric motors of railway locomotives to the frame of the trolley is considered. As a result of the analysis, a classification that makes it possible to systematize the design of suspensions of traction electric motors for all known types of drives, as well as suspensions of axial gears is proposed. [ABSTRACT FROM AUTHOR]

The article discusses the possibility of using the object model for constructive solutions of devices to increase the tractive qualities of locomotives. The proposed approach has been tested on the example of creating a device to improve the traction qualities of a locomotive by applying a magnetic field to the wheel-rail contact area. The use of the proposed device will reduce the losses associated with eddy currents induced by the magnetic field in the wheels and the rail, as well as reduce the probability. [ABSTRACT FROM AUTHOR]

As part of the procedure for diagnosing technical devices operating at production facilities, specialists of the department performed vibration-diagnostic testing of equipment of a number of enterprises in Kharkov and Kharkov region. Using the example of diagnosing the technical condition of diesel power units, we consider the formation of vi-bro-acoustic characteristics of the internal combustion engine (ICE) and the features of conducting an extended analysis of vibration parameters, identifying typical equipment defects. [ABSTRACT FROM AUTHOR]

In this paper, consider the direct problem of mathematical physics on calculating the effect of a concentrated action at some point of a loaded elastic body. As the object of study, a rectangular homogeneous strip plate was chosen, loaded by a concentrated action and having a negligible bending stiffness. The goal is to con-struct a solution in an analytical form and analyze the problem of oscillations of a homogeneous membrane under the influence of a known load. The results of modeling the effect of point action on a homogeneous membrane are presented. The analysis of the mathematical model is based on the obtained analytical solu-tion of the homogeneous two-dimensional wave equation. Modeling was performed using the Maple computer algebra system. The results of modeling the influence of a given point oscillatory action on a specific homo-geneous membrane-strip are presented in graphical form. [ABSTRACT FROM AUTHOR]

The article is devoted to studying the influence of dynamic loading on the polymer element characteristics of rolling stock shock absorbers and to the description to creating a mathematical model of their work. The results of mathematical modeling are further used to solve problems of the rolling stock longitudinal dynamics. While studying, the initial loading rate varied, the room temperature and the effect of the wear factor remained unchanged. For the operating speeds of a freight car movement, a mathematical model of RMCP (rectangular, metal-ceramic, polymer) -110 draft gear was determined. [ABSTRACT FROM AUTHOR]

The article describes the approach to steel planar trusses reliability analysis based in p-boxes (probability boxes). Modeling of stochastic parameters in the form of p-boxes is justified for structural elements due to the significant variability of climatic loads, physical and mechanical properties of structural materials, installation tolerances, and other uncertainties. The advantage of the proposed approach is that it can be used for incomplete (limited) statistical data: when it is difficult to determine the cumulative distribution function (CDF) or CDF's parameters of a random variable. The article presents the different options for p-blocks construction for various types of incomplete statistical data: for an unknown cumulative distribution function using Chebyshev's inequality, for interval estimates of CDF's parameters of random variables, etc. Information about the possibility of performing basic algebraic operations on p-boxes is provided. The failure probability of a structural element will be represented in interval form using the proposed approach. If the range of the interval is too wide (uninformative), then the quality of statistical data should be improved by conducting additional tests of control samples. The article also shows the possibility of using the proposed approach in most practical tasks in the construction industry for the safety assessment of statically determinate trusses. As a result, the special equations are given for evaluating the reliability of a truss as a conditional mechanical sequential system (in terms of reliability theory). The algorithm of reliability analysis is considered on the numerical example. The proposed approach can be used for other types of statically determinate hinge-rod systems. [ABSTRACT FROM AUTHOR]

The article is devoted to the moment method, according to the principles of which it is possible to determine the loads that occur in the thin-walled shell of the orbital vehicle hulls from the action of an internal pressure evenly distributed over the area, normally oriented to the middle surface of the shell. In this case, the load on the shell consists of normal forces (longitudinal and circumferential), the transverse force that causes radial displacements in the shell, and the bending moment in the longitudinal plane of the object. The specified bending moment may occur when inertia forces (for example, the Coriolis force) are manifested when an orbital vehicle moves from one orbit to another in vertical directions normal to the orbit (rotary movements); the same rotary movements may cause inertial forces to occur when maneuvering spacecraft and rocket blocks at the same height (in conditionally horizontal directions). To determine the above-mentioned loads and radial displacements of the shell, a mathematical algorithm is proposed that is based on the principles of the moment method of calculation according to the infinitely long shell scheme, which is typical for orbital vehicles. [ABSTRACT FROM AUTHOR]

The article reviews the results of the research carried out on the properties of a special elastic element of a furnace platform with a movable base. An analytical model of its movement is developed. The model is differed by an inclined "skeletal" curve of its amplitude-frequency characteristic. The research of the dynamics of the elastic-mass system of the platform with a one-sided elastic element in the form of a flattened elastic ring was carried out. The element provides a marked nonlinear elastic characteristic of the system. It was confirmed that the system performs non- symmetric vibrations with peak values of vibration acceleration 5.17 and 1.17 m/s2 corresponding to the extreme positions and differing by four and a half times. The effect of vibratory transportation of bulk material along the horizontal surface of the movable base of the furnace platform in the thermal field of its heating system has been confirmed. [ABSTRACT FROM AUTHOR]

The article is devoted to estimate of polyethylene-modified polypropylene frost resistance, used as an insulating material for cable products. The standard method for testing of polymer material frost resistance is a drop weight impact test on insulated conductors samples at low temperature. To check this parameter at the stage of incoming polymer inspection to use dynamic mechanical analysis (DMA) is proposed. As a result of experimental research by DMA a criterion for estimate of polyethylene-modified polypropylene frost resistance was established. [ABSTRACT FROM AUTHOR]

In general, the conference participants stated that applied mechanics is developing in all directions: railway transport, space industry, aviation, machine tool construction and others. The International Conference "Problems of Applied Mechanics", organized by Bryansk State Technical University, was attended by specialists from industry research and training institutes, manufacturing enterprises and other organizations. [Extracted from the article]