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Modernization of the electromagnetic vibration stand for testing aviation industry products
Full text linkThe article presents a methodology for modernizing a two-mass resonant electromagnetic vibration stand for testing parts of the aviation industry for vibration resistance. The main goal of the modernization is to provide a significantly lower disturbance force from electromagnetic vibration exciters to set the working body in motion. For this purpose, by introducing a third oscillating mass into the two-mass mechanical system, the interresonant mode of operation of the vibration stand is ensured. Analytical dependencies are presented that reveal the methodology for calculating inertial and stiffness parameters that ensure the transformation of a two-mass resonant vibration system into a three-mass interresonant vibration system. A specific example demonstrates the implementation of the proposed approach in the modernization of the design. The amplitude-frequency characteristics of the basic two-mass resonant and modernized three-mass interresonant vibration systems are constructed. It has been confirmed that to ensure the specified amplitude of oscillations of the working body in the modernized design, 4 times less disturbing force from electromagnetic vibration exciters (400 N) is required
Mathematical modeling of the rotating drum granular fill flow oscillatory stability
Full text linkDrum-type machines have become widely used in many industries for processing various granular materials. An innovative direction for significantly increasing the energy efficiency of such equipment is the use of self-oscillating working processes. Self-excitation of auto-oscillations allows you to bring into pulsating flow and activate the passive part of the intra-chamber filling and significantly enhance the interaction of granular particles with each other and with the surrounding environment. The purpose of the study is to build a mathematical model of the conditions and factors of oscillatory instability of the flow of polydisperse granular filling in the chamber of a rotating drum. The research methodology includes analytical modeling of wave processes and experimental modeling of manifestations of instability of the filling flow. The inertial mode of flow of the active part of the filling in a shear flow state is analyzed, the behavior of which is described using averaged values. Based on the results obtained, an increase in instability with an increase in the dilatancy of the medium during deformation is established and the destabilizing effect of the damping action of the fine fraction on the interaction of particles of the coarse fraction is revealed. The main scientific novelty of this study is the identification of the regularities of the unsteady motion of the oscillatory system of a filled drum. The study confirms the possibility of generating, under certain conditions, self-excitation of auto-oscillations of the intra-chamber filling, which is a decisive factor in the predicted intensification of the technological process. The results obtained are valuable for researchers and engineers involved in the study and design of innovative energy-efficient working processes of drum machines
Identification and analysis of pavement structure features based on vibration behavior parameters
Full text linkTo clarify the correlation between the service performance of asphalt pavement structures and their vibration behavior parameters, this study focuses on asphalt pavement structures as the primary research subject. A quarter-vehicle two-degree-of-freedom model of a standard vehicle was selected as the simplified vehicle dynamics model, while a semi-rigid asphalt pavement was adopted as the simplified pavement model. Based on the elastic layered system theory, a three-dimensional finite element model of the asphalt pavement was constructed by using the software of Abaqus. The effects of modulus variations in asphalt pavement structural layers on modal frequencies were analyzed. The impacts of coupled working conditions, such as structural layer cracking positions and interlayer failure, on the modal frequencies of asphalt pavement were investigated. Additionally, the attenuation process of dynamic responses in asphalt pavement structures under transient impact loads was examined. Building on this, the dynamic response behaviors of asphalt pavement structures under working conditions including structural layer cracking and interlayer failure were studied. The results demonstrate that as the vertical depth of the asphalt pavement structure increases, the modulus attenuation of structural layers significantly affects the overall modal frequencies and vibrational effects. When internal cracking and interlayer failure coexist in the asphalt pavement structure, the vibration acceleration characteristics under load align more closely with those of interlayer failure, while the vibration displacement exhibits greater magnitudes
Research on optimization of intelligent driving
Full text linkTrajectory tracking control is one of the most fundamental and important technologies in intelligent vehicles. In response to the problems of low accuracy and poor reliability in current intelligent vehicle path tracking control, the shortest time to complete path tracking of double lane changing was set as the control objective and the optimal control problem for vehicle path tracking is transformed into a nonlinear programming problem using the multi-interval Radau pseudospectral method, and then solved by the sequential quadratic programming method. Through Carsim and MATLAB/Simulink platforms, a joint control simulation of the control algorithm was conducted under double lane changing condition, and finally verified through virtual experiments. The joint simulation and virtual experiment results show that the intelligent vehicle path tracking control algorithm proposed in this paper has good tracking accuracy and driving stability while ensuring the target path tracking performance of the intelligent vehicle. The average values of lateral error and heading error are calculated to be 0.0912 m and 0.0263 rad, indicating that the lateral error and heading error of path tracking are controlled within a small error range during the path tracking process which indicating that the proposed method has high computational accuracy
Muti-objective optimization of tuned liquid column damper design parameters for vibration control under wind load
Full text linkTuned Liquid Column Dampers (TLCDs) are widely used as passive devices for vibration control in structures dominated by wind loads, utilizing the oscillation of liquid in a U-shaped container to dissipate energy. The effectiveness of TLCDs is significantly influenced by key design parameters, like mass ratio, tuning frequency ratio, and head loss coefficient. This study developed governing equations of TLCDs and investigated the influence of external load excitation spectrum on the vibration mitigation performance. A multi-objective optimization approach based on the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was proposed to identify optimal design parameters of TLCDs under various loading conditions. The results revealed that the external excitation spectrum played a crucial role in determining the optimal parameters, and the damper performance was distinctly different when the excitation frequencies changed. This optimization method was validated through a 200-meter high tower, where the optimized TLCD significantly enhanced vibration control performance at a wide range of wind directions. These findings offered valuable insights for the application of TLCDs in complex environments with varying external load characteristics
Engineering protection of the subgrade from sand drifts using geomaterials, as exemplified by the Bukhara-Miskin railway line
Full text linkIn arid regions of southwestern Uzbekistan, protecting the railway subgrade from wind-blown sand is a priority engineering task. This paper presents a systems approach to selecting and applying geomaterials for the Bukhara–Misken railway: climatic-geotechnical zoning, assessment of sand-drift intensity, a decision matrix based on wind loading, and a techno-economic evaluation. The proposed measures (geogrids, geotextiles, geomats, aerodynamic barriers, and biopolymer stabilizers) enhance subgrade stability, reduce maintenance costs, and extend maintenance intervals. The approach is transferable to transport infrastructure in desert zones of Central Asia
A vision-based deep learning approach for non-contact vibration measurement using (2+1)D CNN and optical flow
Full text linkThis paper introduces a proof-of-concept vision-based deep learning approach for vibration measurement, proposing a factorized (2+1)D Convolutional Neural Network (CNN) model to predict four vibration metrics: acceleration, velocity, displacement, and frequency, with a focus on rigid body motion. Unlike conventional neural network models that primarily focus on frequency prediction alone, this approach uniquely enables the simultaneous estimation of four critical vibration metrics, offering a comprehensive and cost-effective alternative to traditional contact-based sensors such as accelerometers. The framework relies on the visibility of a training fiducial marker, eliminates the need for calibration in controlled settings, enhancing scalability across specific environments. A curated dataset was generated using a controlled experimental setup comprising a single object in a lab-scale environment, augmented synthetically to enhance frequency diversity. An optical flow-based preprocessing algorithm synchronized motion features in recorded video inputs with measured vibration labels, improving measurement accuracy. The proposed model achieved an average Mean Absolute Percentage Error (MAPE) of 7.51 %, with acceleration predictions exhibiting the lowest error at 4.84 % and displacement the highest at 8.80 % across varying brightness levels and object-camera distances. Techniques such as Region of Interest (ROI) cropping and multi-section frame extraction were implemented to reduce computational complexity while further enhancing accuracy. These results highlight the framework’s potential for non-invasive vibration analysis, though its generalizability is limited by the single-object dataset. Future work will expand the dataset, integrate multi-sensor inputs, explore marker-less tracking methods, and enable real-time deployment for predictive maintenance and structural health monitoring
Improvement of the system for reporting the state of the electrified railway contact line
Full text linkEnsuring the stable and reliable operation of electrified railways requires continuous monitoring of the overhead contact line (CL), whose mechanical displacement under wind loads can lead to interruptions in power transmission, pantograph detachment, and safety hazards. Traditional inspection and monitoring systems are limited in responsiveness and cannot provide real-time information about the dynamic state of the CL. This study presents an improved contact line deviation reporting system based on distributed Signal Processing and Transmission Modules (SPTM) and Signal Reception Modules (SRM) connected through a GSM wireless communication network. Each vibration sensor installed on the catenary wire continuously measures the displacement amplitude, converts the analog signal into digital form, and transmits it to the dispatcher or driver in real time. The developed modules were implemented using microcontrollers with embedded wireless interfaces, allowing autonomous operation powered by solar-assisted batteries and ensuring electromagnetic protection under high-voltage (25 kV) conditions. Field experiments were carried out on an electrified railway test section near the Tashkent depot to evaluate the system’s performance in real environmental conditions – including wind speeds of 5-18 m/s, ambient temperatures from –10 °C to +38 °C, and during snow and rain. The results confirmed stable data transmission up to 1 km distance with signal delay below 0.8 s and detection accuracy above 95 %. The proposed system thus enables real-time monitoring, automatic warning, and high reliability of communication even under harsh weather conditions, significantly improving the safety and efficiency of train operation. The novelty of this work lies in the practical validation of a GSM-based monitoring network for contact line deviation detection that integrates autonomous power supply, environmental robustness, and real-field reliability testing – aspects that are rarely demonstrated in previous studies
Evaluation and modeling of airborne dust pollution in the Kamchik railway tunnel during train movements
Full text linkThis paper presents the results of a study on airborne dust pollution in the Kamchik Railway Tunnel caused by train movements. Field measurements were carried out to determine the concentrations of suspended particulate matter (PM10, PM2.5, PM1), as well as air temperature, pressure, and humidity in different sections of the tunnel – near the portals and in its central part. It was established that during train passages, the level of dust concentration increases by 6-10 times compared to background values, exceeding sanitary and hygienic standards. The main sources of dust generation were identified as frictional interactions between wheels and rails, braking processes, and the transportation of bulk materials. To reduce dust concentrations, engineering solutions are proposed, including the implementation of automatic water-based dust suppression systems, enhanced tunnel ventilation, and the use of hydrophobic surface coatings. The obtained results can be used to optimize ventilation modes and improve the operational safety of the Kamchik Railway Tunnel
The properties of self-compacting fine-grained concrete mixtures for energy-efficient vibration-free construction technologies
Full text linkThe article presents the results of the development and research of self-compacting fine-grained concrete mixes for energy-efficient vibration-free construction technologies. The main focus is on selecting optimal compositions that ensure the required level of mobility and self-compaction through a rational ratio of components and the use of complex modifying additives. The results of research into the rheological characteristics of concrete mixtures, as well as the physical and mechanical parameters of the materials obtained, are presented. The patterns of the influence of the composition and structure of concrete on its density, strength, water absorption and deformability have been established. The results obtained confirm the possibility of creating effective self-compacting fine-grained concretes with high structural homogeneity and reduced energy consumption during production and laying