Journal of Mechanical Engineering, Automation and Control Systems
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Data analytics-based model for optimizing cationic retarder and acetic acid in polyacrylic yarn dyeing
Get PDFThe study aims to develop a model for optimizing the concentration of solution parameters in the dyeing process of polyacrylic yarns. Specifically, the study examines the use of cationic retaiders and acetic acid, which affect the wavelength as an indicator of yarn color aging. By optimizing these parameters, the objective is to improve the color stability and longevity of dyed polyacrylic yarns. The application of Response Surface Methodology (RSM) encompassed two distinct types of data distribution properties: linear and non-linear. The R-squared (R2) value for the non-linear RSM model was 0.96, compared to 0.86 for the linear RSM model. These results indicate that the model formed based on the non-linear RSM offers superior predictive ability in optimizing solution concentration as a parameter in the polyacrylic yarn dyeing process compared to the linear RSM-based model. In addition to providing practical implications for textile practitioners, this study contributes theoretically by emphasizing the effectiveness of statistical methods such as RSM in manufacturing process analysis
High-speed roller/rail dynamics and thermodynamics considering surface roughness and revolution
Get PDFConsidering rotation and not considering rotation, a calculation was conducted on the friction and wear between the sliding pair in a high-speed rotating machine using a plane of Ra6.3 and Ra3.2, indicating that Ra3.2 has advantages. In higher firing rate Gatling guns, the guide rail should be processed more finely and have a smaller roughness. The results demonstrate that the stress increases a lot when the bolt is surface rough, which is 11.5 % higher than the flat condition. The temperature of Ra6.3 is about 100° higher than the flat condition. It plays an important role in improving the service life of friction surfaces
Vibration velocity control of compound wedge-shaped excavation blasting in tunnels under complex environments
Get PDFThis paper explores the optimization of cutout schemes in tunnel excavation and blasting by introducing an improved segmented wedge-shaped blasting method, validated through both numerical simulations and field tests. The numerical simulations use the ANSYS/LS-DYNA fluid-solid coupling algorithm to analyze the damage effects, effective stress distribution, and vibration characteristics of surrounding rock for both the Conventional wedge cut and the segmented wedge cut methods. The results show that segmented wedge cutting significantly enhances the utilization rate of blast holes, reduces the formation of large gravel fragments, and effectively mitigates surrounding rock vibration velocities. In comparison to the Conventional method, the optimized undercut scheme not only increases blasting efficiency but also greatly enhances the rock fragmentation in the undercut area, thereby ensuring tunnel construction safety. The field test results validate the accuracy of the numerical simulations and show that the enhanced scheme holds significant potential for practical application in real-world projects
Application of unsupervised identification of dissolved gases in transformer oil based on spin coating film making process
Get PDFAddressing the issues of low efficiency and uneven collection of dissolved gases in transformer oil leading to overfitting and poor performance of identification models, we propose a novel film-making process that integrates Gaussian process and unsupervised pre-classification to enhance the recognition efficiency of dissolved gases in transformer oil. This method not only forms a thinner and more uniform separation layer, significantly improving degassing performance and collection efficiency, but also addresses the problems of insufficient data labeling and sample imbalance by introducing the K-means++ clustering algorithm and pseudo-random integration technology, thereby enhancing model robustness and generalization ability. Moreover, the designed Gaussian Process Multi-Classification (GPMC) method employs probabilistic interpretation for result presentation, which increases the accuracy of fault identification. Experimental results show that under consistent starting conditions, the RCC and ARI indicators of our pre-classification method are close to 0.8, with the test set’s recognition rate exceeding 80 %, while the GPMC method misclassified only 2.4 % of the cases in the 1800-case dataset. These improvements make our method particularly effective for handling uncertainties and imbalances in dissolved gas cases in transformer oil, showcasing its potential for practical applications
Stodola-Vianello iteration method for the free flexural vibration frequencies of Shimpi’s single variable shear deformable beams
Get PDFThe natural vibration frequency analysis of beams is vital for their design against resonance failures because such failures occur when the excitation load frequencies of vibration coincide with such natural frequencies. This work presents a single variable shear deformable beam equation formulated using Shimpi’s displacement field assumptions. This results in a quadratic shear stress profile over the depth and a satisfaction of the transverse shear stress-free boundary conditions. The governing equation is obtained using a first principles consideration and equilibrium method as a partial differential equation (PDE) which is non-homogenous for forced vibrations and homogeneous for free vibrations. The study then used the Stodola-Vianello iteration method to solve the resulting homogeneous PDE for simply supported boundary conditions and harmonic response. The problem reduced to an iterative problem of algebra involving the computation of an (n+1)th vibratory modal shape function from an nth shape function that satisfies the boundary conditions. This work used a sinusoidal shape function which is exact for the simply supported boundary condition investigated. The use of boundary conditions solved the integration constants involved. Application of the convergence rule led to the eigenequation from which the eigenvalues were found. The eigenvalues were presented for the first four modes of vibration and for a rectangular beam. It was found that for l/h varying from 5 to 100, the natural vibration frequencies were identical with the ωn values obtained using Navier method for other thick beam vibration problems. It was also found that ωnwas close to the exact values for all vibration modes and for all values of l/h between 5 and 100. For all vibration modes and all considered l/h values negligible differences, were observed between the ωn obtained using SVIM and the exact values obtained by previous researchers
Reinforcement of the embankment with reinforced concrete piles in the transition zone from the railway embankment to the bridge
Get PDFThe article presents the design of the transition section to be used in different conditions in the region of junction of roadbed and the bridge, establishment and reasons of vertical shifts under the action of vibro-dynamic forces which appear when trains are driven along transition section. Likewise, in the sections of the foundation of the roadbed and the bridge, the types and types of a variety of defects caused by this fact, such as when the pressure of the weight of constant and temporary forces dropped on the rolling stock passes the active pressure of the ground (Ea), which acts on the support of the bridge shore at the point of the passage, are provided. In order to minimize the active effort at the junction formed by soil, reinforce and make the junction location defect-free, reinforced concrete piles are driven into the embankment to act as bases of junction location between the roadbed of the railway and the bridge location and a formula of computing the spacing of the piles has been contributed taking into consideration outer influences
Modern strengthening techniques for enhancing the load-carrying capacity of in-service road bridges in Uzbekistan
Get PDFThe sustained growth of traffic intensity and axle loads in Uzbekistan has accelerated the deterioration of in-service road bridges, making cost-effective strengthening a national priority. This paper presents a structured review and comparative assessment of strengthening approaches grouped into: (i) traditional cross-section enlargement and substructure rehabilitation, (ii) structural scheme optimization and dead-load reduction (including external prestressing and span continuity), and (iii) advanced solutions based on carbon-fiber-reinforced polymers (CFRP). A worked example for a typical reinforced-concrete girder span demonstrates the compensation of a deficient bending moment of ΔM= 70 kN·m and indicates an ~18-25 % increase in load-carrying capacity after strengthening. The paper further synthesizes implementation considerations for arid-continental climates, including surface preparation, adhesion control, protective coatings, and staged load testing. Drawing on regional practice, CFRP systems are highlighted as offering high strength-to-weight benefits, installation speed, and minimal traffic disruption; reported gains for flexural elements typically range from 25 % to 45 %, subject to detailing and quality assurance. The results support integrating CFRP-based measures and complementary dead-load optimization into bridge rehabilitation programs in Uzbekistan, with recommendations for monitoring intervals (6-12 months) and future durability studies on adhesives and UV/moisture protection. Overall, the study consolidates methods and provides quantitatively grounded guidance for extending service life under contemporary traffic demands
Analysis of the influence of vibration phenomena in pump systems on electrical energy consumption and operational efficiency
Get PDFDespite the long-standing recognition of vibration phenomena as a critical factor affecting both mechanical reliability and energy performance, yet their influence on electrical energy consumption remains insufficiently quantified. Excessive vibration, originating from rotor imbalance, shaft misalignment, bearing wear, and hydraulic instabilities, can result not only in accelerated component degradation but also in significant increases in energy demand and reductions in hydraulic efficiency. Understanding the quantitative relationship between vibration intensity and pump energy performance is therefore essential for both predictive maintenance strategies and energy efficiency improvements in pumping systems. This paper presents an experimental investigation of the effect of vibration on the electrical energy consumption and operational efficiency of centrifugal pumps. Five industrial pump types, with rated powers ranging from 15 to 75 kW and capacities from 100 to 320 m3/h, were tested under controlled conditions. Measurements were carried out using UT310A vibration testers, an ultrasonic flow meter, and a Fluke 1777 Power Quality Analyzer. Vibration signals, volumetric flow rates, pressure heads, and three-phase electrical parameters were simultaneously recorded under partial load, nominal load, and overload conditions. Hydraulic power and efficiency were then calculated, while statistical analyses-including correlation and regression models-were applied to determine the relationship between vibration intensity and electrical performance. The results revealed a strong positive correlation between increasing vibration levels and higher electrical energy demand. In particular, RMS vibration acceleration was found to be a reliable predictor of additional energy losses, while efficiency was observed to decrease as vibration intensity increased. These findings not only confirm the detrimental effect of mechanical instability on energy consumption but also provide a methodological framework for integrating vibration monitoring into energy management practices. By bridging the gap between mechanical diagnostics and energy performance analysis, the study contributes new insights that can support the development of predictive maintenance systems, improve pump reliability, and promote more sustainable operation of pumping stations
Analysis of the structural performance of reinforced concrete under fire loading
Get PDFThis study examined the behavior of reinforced concrete structures when exposed to high temperatures resulting from fire. Deterioration in material strength due to fire exposure alters a reinforced concrete structure’s load-bearing capacity and overall behavior. Elevated temperatures negatively affect key material properties of reinforced concrete, including density, coefficient of thermal expansion, thermal conductivity, and elastic modulus. As a result, if a structure experiences fire either concurrently with or prior to an earthquake, these changes in material properties will significantly influence its dynamic performance. For the numerical simulation, the selected structure was designed with a formwork plan and load-bearing system in accordance with earthquake-resistant design principles. Based on this design, fixed and variable loads acting on the beams were assigned. By promoting resilient infrastructure capable of withstanding severe environmental conditions such as earthquakes and fires, this study contributes to the achievement of sustainable development goals. It underscores the necessity of integrating fire resistance into earthquake-resistant design to foster disaster-resilient urban development. The findings may encourage more flexible and sustainable construction practices aligned with SDGs 9 (Industry, Innovation and Infrastructure), 11 (Sustainable Cities and Communities), and 13 (Climate Action)
Vibration-resistant mixed binders using man-made burnt rocks for transport infrastructure
Get PDFThis study presents the characteristics of man-made wastes, specifically burnt rocks formed by the self-combustion of coal-bearing waste dumps, whose chemical and mineralogical composition depends on the origin of the basin. The aim of this research is to assess the feasibility of using these burnt rocks as components of mixed mineral binders and to evaluate their influence on mechanical and dynamic performance parameters. A comprehensive analysis of their physical, chemical, and structural properties was carried out, demonstrating their compatibility with conventional binder materials. The novelty of this study lies in the first systematic use of locally available burnt rocks (glyage) in vibration-resistant binder compositions for transport infrastructure, expanding the raw material base of construction materials while reducing environmental impact. The developed binders achieved compressive strengths up to 17.6 MPa, sufficient for structural layers of pavement bases and subgrade stabilization. Moreover, these mixed binders can modify the dynamic stiffness and damping behavior of pavement structures under moving vehicle loads, establishing a scientific link between binder composition and vibration control in transport engineering. These results are directly relevant to vibration engineering, as the dynamic stiffness and damping behavior of the developed binders influence vibration propagation and attenuation in transport pavements, ensuring longer service life and reduced noise and deformation under dynamic traffic loads