Eastern-European Journal of Enterprise Technologies

Determining patterns in the longitudinal loading of the modernized carrier structure of an open wagon for transporting long cargoes

2026-01-16T19:19:00+02:00

This study investigates processes related to the occurrence, acceptance, and redistribution of loads in the modernized supporting structure of a railroad open wagon. The task addressed is to improve the efficiency of transporting long-length cargo by rail.

The work proposes that the bearing structure of an open wagon should be modernized by dismantling the end walls or doors. This makes it possible to reduce the sprung mass of the bearing structure of the open wagon by more than 1 t and, accordingly, to increase the load capacity by the same amount.

To substantiate the proposed modernization, the strength of the bearing structure of an open wagon moving in a train was calculated. The longitudinal loads acting on the bearing structure of the open wagon were determined by mathematical modeling. The calculated acceleration value was taken into account when studying the stress state of the bearing structure of the open wagon. It was established that its strength is maintained as the calculated stresses are 14.5% lower than the permissible ones. In addition, as part of the study, a modal analysis of the bearing structure of the open wagon was conducted. The calculation results showed that traffic safety from the point of view of modal analysis is observed.

A feature of the proposed modernization is that, if necessary, the bearing structure of the open wagon can be returned to the original version.

The scope of practical application of the reported results is the transportation industry, in particular railroad transport.

A condition for practical use of the results is symmetrical loading of the bearing structure of the open wagon with cargo.

This study could contribute to compiling recommendations for increasing the efficiency of transportation of long-length cargo by rail.

Definition of reliability parameters of the spacer plate of a jaw crusher depending on the characteristics of the working environment and the material of manufacture

2026-02-26T10:45:54+02:00

The object of the study is the spacer plate of a Jaw crusher. The Jaw crusher is the main machine in the crushing and sorting scheme. An unexpected failure of one of the crusher parts leads to a stoppage of the entire scheme. One of the important parts of the crusher is the spacer plate, which is in a complex, alternating stress state.

The paper investigates the reliability parameters of the spacer plate of a jaw crusher in the processes of crushing crushed stone, which is an aggregate in the manufacture of concrete. The calculation of the strength of the spacer plate in existing methods is carried out using empirical formulas. A number of functional methods are also used. However, most functional methods have inherent shortcomings that are built on statistical approaches, which can lead to inaccurate reproduction of the picture of the failure of machine elements. In the work, the problem is solved by using a combined model, namely the linear damage accumulation algorithm in combination with a finite element model to which the Weibull distribution is added, which is the most universal method of functional distribution for determining the limit states of parts and machine assemblies. Such a solution allows to determine the reliability parameters and establish a real picture of the process. A solid-state model of a jaw crusher has been developed and the loads applied to the spacer plate have been calculated.

Using the nCode EN Constant and nCode EN TimeSeries presets, which are built into the ncode DesignLife product of Hottinger Baldwin Messtechnik GmbH (Germany), the parameters of the failure life and fatigue strength of the crusher spacer plate were determined. In the nCode EN TimeSeries preset, the WeibullAnalysis glyph was used for data analysis. The results of the study can be used in studies of a wide range of machines to determine the limit states of machine parts and assemblies

Effect of concentrated impulse loading (impact) on massive, glulam, and cross-laminated timber beams

2026-02-25T16:50:26+02:00

In this study, massive, glulam, and cross-laminated timber beams of rectangular cross-section were examined under a concentrated impulse loading (impact).

The task addressed was to determine and compare the deformation and dynamic characteristics of beams made of different types of timber under short-term impact.

During experimental studies, dependences of displacements over time were established; oscillation oscillograms were constructed; spectral analysis was performed, and the frequencies of free oscillations (f_MT,exp = 75 Hz, f_GLT,exp = 73 Hz, f_CLT,exp = 67 Hz) and logarithmic damping decrements (β_MT,mean = 0.222, β_GLT,mean = 0.100, β_CLT,mean = 0.092) were determined for each type of beam. It was found that a cross-laminated timber beam is characterized by the lowest deformation resistance and the lowest oscillation damping rate. Glue-laminated timber (glulam), in comparison with solid timber, demonstrates a smaller maximum displacement and a lower oscillation damping rate.

The results are attributed to the peculiarities of internal structure of the materials, the orientation of the fibers, the presence of adhesive layers, and the nature of the interlayer interaction, which significantly affect the stiffness, damping properties, and distribution of impact energy.

A distinctive feature of the findings is the experimentally confirmed comparison of the dynamic response of beams made of different wooden based materials under the same loading conditions, which made it possible to reasonably assess their effectiveness under the action of impulse influences and solve the research problem.

This study's results could be used in the design of timber load-bearing elements of buildings and structures subjected to dynamic or impact loads, as well as to refine calculation models, determine dynamic coefficients, and assess the effectiveness of using solid, glued, and cross-glued wood

Patterns in the formation and parameterization of the fracture system emerging during a multi-stage hydraulic fracturing in tight reservoirs under different modeling approaches

2026-01-21T18:11:57+02:00

A system of artificially created fractures formed during multi-stage hydraulic fracturing in a low-permeable gas-saturated reservoirs has been investigated in this study. The task addressed is to parameterize the object under consideration given limited input geomechanical information.

The results of hydraulic fractures modeling have been obtained, as well as their geometric and filtration parameters, by using analytical and explicit numerical methods. Interpretation of the findings revealed the limitations in analytical methods when considering the geomechanical properties of rocks; specifically, their reservoir and geomechanical heterogeneities and stimulation design. The consequence is the greatly increased uncertainty in production forecasting because fractures are represented by average values of key parameters (L = 120–330 m, w = 2.4–7.8 mm) for determining well productivity.

The explicit method demonstrated higher flexibility and adaptability depending on the available input data. The average results, which were obtained by applying both methods, showed similarity between key parameters (L = 199–339 m, w = 7–10 mm, Cf = 774–1098 mD*m), which confirms these methods' validity. However, the ability of the explicit modeling approach to provide a detailed description of key fracture parameters, including 3D geometry, variation of fracture width (w = 3–11 mm), and proppant saturation over the fractured area (Cp = 75%), gives a higher priority to this method during research.

The use of an explicit method, in contrast to the analytical one, makes it possible to determine the asymmetry of the fracture flanks, relative to the direction of the minimum horizontal stress, the change in thickness and permeability along the fracture, the distribution and concentration of proppant. All this leads to an uncertainty ranges reduction in the production forecast from horizontal wells with multi-stage hydraulic fracturing, during the development of shale reservoirs. This is the next step for further use of the results.

Construction of the discrete-continuous mathematical model of a hysteresis damper impact device

2026-02-27T15:13:20+02:00

This study investigates the process of interaction between the impact device tool and its body elements during an impulse response from the processing medium in the presence of a hysteretic damper of mechanical vibrations. The task addressed is to build a mathematical model with hysteresis damping of oscillations of the impact device elements.

In the mathematical model, the tool is represented by a rod of variable cross-section, and the body parts of the hydraulic hammer are represented by a discrete element with a reduced mass. To damp mechanical oscillations, a rheological model of the hysteresis type is used. The impact interaction of the device elements is modeled by the presence of rigid and dissipative connections. The motion of the impact device elements is described by a system of nonlinear differential equations.

The combination of discrete and continuous types of models has made it possible to solve the task of synthesizing a mathematical model. A comparison for the discrete-continuous model and the discrete model of hysteresis curves justifies their correctness. The proposed model makes it possible to estimate the energy consumption for damping and the distribution of stresses along the length of the tool. When the recoil force changes in the range of 50–500 kN for 1 ms, the energy losses were up to 500 J, and the stress in the conical part of the tool was up to 560 MPa.

To solve the initial-boundary problem, a numerical method is used, which includes the finite difference method and the Euler scheme with linearization. The parameters of the numerical method were determined using a discrete two-mass model. The length step is 0.005–0.01 of the tool length, the time step is 0.001–0.05 ms.

The model could be used in the design of rock development devices and impact systems to increase hydrocarbon production in the oil industry

Construction of a generalized mathematical model for particle sliding on the surface of a rotating vertical straight helicoid

2026-02-11T20:58:37+02:00

The object of this study is the complex motion of a particle on the surface of a vertical straight helicoid rotating around its own axis. In screw conveyors, closed helicoids are used as well-known technical helical surfaces. An issue is not the disadvantages of using classical closed helicoids but the limitations of existing mathematical models of particle motion, which essentially reduce engineering research only to this type of surfaces. The lack of a generalized model for other helical surfaces makes their analysis and practical application impossible. The proposed approach expands the class of helicoids under consideration and creates the prerequisites for finding new design solutions.

The derived second-order differential equations describe the trajectory of particle sliding on the surface. Depending on the structural parameters, such a surface can be an open or closed helicoid, as well as a special case of rotation of a horizontal flat disk. That has made it possible to define the parameters of particle motion on different surfaces and compare the results. In particular, the particle sliding trajectories along closed and open helicoids rotating with angular velocity ω = 10 s^–1 and ω = 20 s^–1 were constructed. In this case, the friction coefficient f = 0.3 and the lift angle β = 15° of the outer edge of the surface were assumed at a radius of R = 0.1 m of the limiting cylinder. The particle sliding trajectories were constructed within the surface compartment, as well as under the condition that it is not limited by the cylinder.

The practical significance of the results is the possibility of using the model built for designing energy-efficient screw conveyors without an external casing. This makes it possible to reduce the metal content of structures by 15–20% and prevent jamming during the transportation of fractional materials. The resulting analytical dependences make it possible to calculate the optimal screw pitch and shaft radius to ensure a given material movement trajectory.

Design of a tumbling machine (mixer) using a statically determinate spatial mechanism and determination of rational geometric parameters

2026-02-10T19:18:37+02:00

The object of this study is tumbling equipment in which working containers execute a complex spatial motion.

Articulated spatial mechanisms are widely used in various branches of industry, particularly in mechanical engineering, including mechanisms that contain passive constraints in their structure. The presence of passive constraints can cause operational problems and negatively affect equipment reliability. Therefore, an important task is the synthesis of articulated spatial mechanisms through modification of existing structures in order to eliminate passive constraints.

This paper reports the synthesis of a statically determined seven-link articulated spatial mechanism with revolute kinematic pairs. A technique for eliminating a passive constraint in the structure of an articulated spatial mechanism has been proposed, which allows for its static determinacy. As a result, the need to compensate for inaccuracies in geometric relationships between the links by means of clearances in the kinematic pairs is eliminated, making it possible to improve operational characteristics and prolong service life.

The introduction of an auxiliary link into the spatial kinematic chain creates conditions for effective implementation of tumbling technological operations by increasing the amplitude of spatial displacement of the container.

Analytical relationships between the main geometric parameters of the seven-link spatial mechanism that determine its operability have been established. The derived mathematical dependences allow a justified selection of rational geometric parameters at the design stage and provide a basis for calculating key geometric characteristics for further engineering application in industrial practice.