Research on expansive soil characteristics – taking Ankang Tunnel as an example

This paper takes the Ankang Tunnel as an example to conduct research on the mechanical characteristics of swelling and shrinkage deformation of expansive soil, such as the free swelling ratio, unloaded swelling ratio, axial load swelling ratio, and swelling pressure, hoping to provide guidance for the construction of similar expansive rock and soil tunnels. The research shows that: (1) The free swelling ratio of the expansive soil in the Ankang Tunnel is relatively low, at 49.7 %, with weak-medium expansiveness. (2) The unloaded swelling process of the expansive soil can be divided into the rapid swelling stage in the initial swelling stage, the swelling transition stage and the slow swelling stage in the middle swelling stage, and the swelling stable stage in the later swelling stage. (3) With the increase of the water content, the swelling pressure of the soil gradually decreases

Experimental and finite element analysis of the structural durability of special self-propelled rolling stock frames

The study presents an experimental-numerical assessment of the structural durability and residual life of the ADM-1 self-propelled railcar frame operating under cyclic and static loading conditions. A combined methodology integrating full-scale cyclic bench testing and finite element modeling (FEM) was developed to determine the frame’s stress–strain state and fatigue resistance. The experimental tests, performed at the accredited laboratory of “Quyuv Mexanika Zavodi” JSC using the ISRB-1000 hydraulic loading stand, simulated real operational loads up to 2×106 cycles, equivalent to approximately ten years of service. A detailed FEM model was created in SOLIDWORKS Simulation to replicate these loading conditions, analyze stress distribution, and validate experimental data. The numerical and experimental results showed strong correlation (r > 0.9) with a deviation below 8 %, confirming the accuracy of the proposed approach. The maximum equivalent (von Mises) stresses remained below 0.6σ0.2 for St3sp steel, indicating that the structure operated entirely within the elastic range and met the strength requirements of GOST 31846-2012. Fatigue life estimation using Miner’s cumulative damage rule yielded a damage factor of D= 0.72, corresponding to 8-12 years of effective service life, with a residual fatigue resource of approximately 35-40 %. The developed hybrid methodology provides a reliable framework for condition-based maintenance and life-extension of special self-propelled rolling stock

Vibration damping and interfacial adhesion behavior of steel-UHMWPE composite structures

Hybrid structures combining steel and polymer layers are widely used in engineering systems where vibration reduction and mechanical durability are required. In this study, a composite structure consisting of a low-carbon steel substrate and an ultrahigh molecular weight polyethylene (UHMWPE) coating was investigated in terms of vibration damping capacity, adhesion strength, and thermal behavior. The UHMWPE coating was applied to the steel surface through a thermal pressing technique under optimized temperature and pressure conditions. The vibration damping performance was analyzed using a modal analysis method and accelerometer-based measurements within the frequency range of 100-1000 Hz. Interfacial adhesion was evaluated via shear and peel tests according to ASTM D1002 standards. Results show that the steel-UHMWPE composite exhibits up to 35-40 % improvement in damping ratio compared to bare steel specimens. The optimal adhesion strength was achieved at a processing temperature of 190 ℃, where the interfacial energy balance between the polymer and steel substrate minimizes delamination. Thermal stability analysis using DSC and TGA confirmed the material’s operational range up to 120 ℃, making it suitable for automotive and mechanical vibration isolation applications. These findings demonstrate that the combination of steel’s stiffness and UHMWPE’s viscoelastic damping behavior offers a promising approach to lightweight vibration control components. Further optimization of interface modification and filler reinforcement is planned to enhance tribological and thermal resistance properties

Small targets detection in low-resolution remote sensing images based on super-resolution joint optimization

While convolutional neural networks have driven remarkable progress in remote sensing object detection, persistent challenges remain in detecting small targets within low-resolution imagery due to their limited pixel representation and feature degradation during hierarchical downsampling. To address this, this study proposed the joint super-resolution and detection network (JSRDN), which synergistically optimizes SR reconstruction through task-specific detection feedback, significantly enhancing small target recognition in LR remote sensing imagery. Firstly, generator in generative adversarial network incorporates improved residual blocks, enabling enhanced perception of complex deep-level features in the SR reconstruction process. Then, a perceptual loss function is introduced into the adversarial training process, which captures perceptual discrepancies in high-level features between reconstructed images and original HR references. After that, an edge-enhancement network is designed to dynamically detect edges in intermediate features restored by the generator, prioritizing edge influence across network layers to generate discriminative features for target recognition. Furthermore, the JSRDN implements detection-driven feedback by backpropagating object recognition loss through the generator, enforcing the super-resolution process to prioritize detection-salient feature recovery. Evaluated on 64×64 low-resolution COWC datasets, JSRDN achieves 0.1819 dB peak signal-to-noise ratio (PSNR) and 7.18 % average precision (AP) improvements over the deep residual dual-attention network (DRDAN), with ablation studies and visualizations confirming its balanced optimization of reconstruction fidelity and detection-oriented feature learning. This technology can provides valuable support for small target measurement and opens new opportunities in the field

Simulation of motion trajectories and kinematic characteristics of an oscillatory system with a planetary-type vibration exciter

The parameters of the vibration exciters significantly determine the efficiency, reliability, and durability of vibratory technological equipment. This article continues the authors’ previous research dedicated to planetary-type vibration exciters. The main objective at this stage is to substantiate the feasibility of using planetary mechanisms as drives for vibratory machinery. The methodology for conducting virtual experiments involves using the “Motion Analysis” application within the SolidWorks software to simulate the motion of an oscillatory system with a planetary-type vibration exciter. The modeling results are presented as time dependencies of displacements, velocities, and accelerations of the oscillating body (the working element of the vibratory machine), as well as its motion trajectories under different geometric parameters of the planetary mechanism. The scientific novelty of the work lies in the further development of methods for exciting oscillations of the working bodies of vibratory machines with predetermined kinematic and force parameters. The conducted research can be useful for researchers and engineers involved in the investigations and designing of vibratory equipment, aiming to ensure the technologically required motion trajectory and kinematic characteristics of the corresponding working bodies (such as conveying trays, sieves, screens, compacting plates, etc.)

Vibrodiagnostics and dynamic operation of reinforced concrete sleepers under the influence of moving load

Vidrodiagnostics is one of the methods of monitoring and diagnosing the railroad track for defects and damages. Determination of vibration (dynamic) impact on the track from the rolling stock load is possible with the help of vibration sensors - velocimeters and accelerometers. The article presents the results of full-scale (operational) tests of reinforced concrete sleepers with different types of bonding on three sections of the railroad mainline. The dependences between the maximum amplitudes of vibration displacement, vibration velocity are determined. The purpose of this study was to identify the main causes of defects in reinforced concrete sleepers by vibrodiagostic method, to identify the greatest attenuation of vibrations of the track structure, damping of vibration from passing rolling stock and determination of the best dynamic operation of the track. This research will help further technological and economic development of railroads, as well as maintain safe operation of the main network of the Republic of Kazakhstan

Analysis and optimization of dynamic characteristics of the supporting frame structure of small fishing boat

The dynamic characteristics of the support frame structure are critical factors influencing the safety and stability of small fishing boat. A prestressed modal analysis model of the support frame was established using the finite element method to evaluate stress, deformation, natural frequency, and modal shapes under maximum bending load conditions. To validate the accuracy of the simulated natural frequencies, the support frame was freely suspended using wide elastic ropes, and a hammering test method was employed, achieving a maximum error of less than 7.5 %. Based on a multi-objective optimization approach, optimal designs with varying thicknesses were developed to minimize stress peaks and maximize natural frequencies without increasing mass. Combining the results from strength and modal analyses, structural improvements such as adding local reinforcing ribs were proposed. Modal simulations confirmed that the optimized design can effectively mitigate low-frequency vibrations and enhance structural reliability

Dynamic analysis of a new type of linear vibrating screen with adjustable vibration direction angle

To address the limitations of conventional vibrating screens, such as restricted operational conditions and poor adaptability, this study proposes a new type of linear vibrating screen with an adjustable vibration direction angle. By altering the fixed positions of the bolts between the vibration motors and motor supports, the angle between the vibration direction and the screen surface can be modified to achieve vibration direction angle adjustment, thereby enabling the screen to adapt to diverse working conditions. Creo and ANSYS Workbench were employed to conduct dynamic analyses of this innovative design, revealing displacement and stress distribution maps under various vibration direction angles. The results demonstrate that the new type of vibrating screen exhibits excellent structural strength and stiffness, effectively meeting industry requirements. This study provides valuable insights into the design of linear vibrating screens

Improved iterative reweighted L1 norm minimization method for sound source identification

Sparse reconstruction algorithm is one of the main research topics in compressed sensing. To address the shortcomings of existing iteratively reweighted l1-norm minimization methods, which exhibit poor performance in low-frequency sound source identification and weak anti-interference capability, this paper proposes an improved iteratively reweighted l1-norm minimization method. Unlike traditional methods, this method introduces a log-sum penalty function and constructs a surrogate function, transforming the problem into an effective form for solving the source strength distribution vector. Through numerical simulations comparing the two methods under different frequencies and signal-to-noise ratios (SNR), the results demonstrate that the proposed method enhances both the sound source identification accuracy and anti-interference capability of the algorithm, while also being able to adapt to lower frequency ranges

Dynamic response and lightweight design of winding drum based on CAE technology

To enhance the rationality of the anchor winch drum structure design and reduce costs and energy consumption, a lightweight design scheme was put forward based on multi-objective optimization technology. According to the working principle, load characteristics, and composition of the anchor winch, a parameterized coupled model of modal and strength was established using the finite element method, from which the stress, deformation, natural frequency, and mode shapes characteristics of the drum part were obtained. Under the premise of not changing the assembly dimensions and not causing structural interference, the dimensions of the cylinder, side panels, and ribs were determined as design variables, and corresponding sensitivity analysis was derived. The maximum stress, first-order equivalent stiffness, and mass were set as the optimization targets, and the Kriging model was used as an approximating function in the construction of mathematical model. The standard criteria for evaluating the precision of the response surface model were chosen as the coefficient of determination, adjusted coefficient of determination, and root mean square error. Under the condition of maintaining equivalent stiffness without degradation, two lightweight design schemes were obtained under the conditions of no less than the initial stress peak value and 1.5 times the stress peak value. The results show that it is possible to achieve a weight reduction rate of 14.1 % without increasing the stress peak value and without reducing the equivalent stiffness, effectively achieving the design goal of energy saving and cost reduction