This paper aims to improve ride comfort for straddle-type monorail trains with single-axle bogies. A dynamic simulation model of these trains was constructed in ADAMS to investigate their motion characteristics. The modeFRONTER software was used to conduct a global sensitivity analysis of suspension system parameters and tire positioning parameters, identifying the key design parameters that strongly impact lateral stability. The improved non-dominated sorting genetic algorithm (NSGA-II) was then utilized for multi-objective optimization, yielding an optimal set of parameters. The final optimization results showed that the front lateral Sperling index decreased from 1.906 4 to 1.601 6, with a 15.99% improvement, and the rear lateral Sperling index decreased from 1.949 1 to 1.631 1, with a 16.32% improvement, indicating a substantial enhancement in ride comfort. The research results provide a theoretical basis and technical support for further improving the operational performance of straddle-type monorail trains with single-axle bogies.
To address difficulties in extracting transmission system fault information from operational locomotives on railways, this paper proposes a diagnostic method tailored to variable-speed conditions by analyzing current signals from traction motors for locomotive gearbox faults diagnosis. As traction motor speed changes linearly, the fault characteristic frequencies of the transmission system also vary linearly but at multiple rates, differing from the motor power supply frequency and gear rotational frequency. Although the fractional Fourier transform (FrFT) is well suited at analyzing linear frequency modulation signals, selecting its optimal order complicates its application. To overcome this, this paper proposes to construct a new hybrid entropy to uniformly characterize the spectral peak sharpness in FrFT and the degree of energy concentration in the frequency domain, and to use it as the fitness function to determine the optimal order through exhaustive search. Experiment results from industrial implementation show that the proposed method can effectively diagnose transmission gear faults in tractor motors.
Purpose – The rapid development of China’s railway construction has led to an increase in data generated by the high-speed rail (HSR) catenary system. Traditional management methods struggle with challenges such as poor information sharing, disconnected business applications and insufficient intelligence throughout the lifecycle. This study aims to address these issues by applying building information modeling (BIM) technology to improve lifecycle management efficiency for HSR catenary systems. Design/methodology/approach – Based on the lifecycle management needs of catenary engineering, incorporating the intelligent HSR “Model-Data Driven, Axis-Plane Coordination” philosophy, this paper constructs a BIM-based lifecycle management framework for HSR catenary engineering. Findings – This study investigates the full-process lifecycle management of the catenary system across various stages of design, manufacture, construction and operation, exploring integrated BIM models and data transmission methods, along with key technologies for BIM model transmission, transformation and lightweighting. Originality/value – This study establishes a lossless information circulation and transmission system for HSR catenary lifecycle management. Multi-stage applications are verified through the construction of the Chongqing–Kunming High-Speed Railway, comprehensive advancing the intelligent promotion and high-quality development of catenary engineering.
Transportation engineering, Railroad engineering and operation
The railway car body is made of aluminium extrusion comprising various rib shapes. The ribs are designed to enhance the stiffness of the car structure. Although the ribs are intended to support large panels of the aluminium extrusion, they can degrade the noise reduction effect owing to multiple resonant vibrations at high frequencies. Therefore, a scientific attempt was made to improve the railway frame by using ribless panels. First, a structural analysis of the original aluminium extrusion was conducted using computer simulation. The simulation results revealed that the ribs of the frames transmitted noise owing to their resonance in the high-frequency range. Therefore, a new railway frame model, named the ribless panel, was developed in this study. Vibration simulations indicated that the ribless panel was effective in reducing noise and vibrations in the high-frequency range. Furthermore, the ribless panel was reinforced with acrylic plastic to reduce the resonant vibrations of the plates. After examining the transmission loss in cross-sectional railway frames, a comparative test of the noise reduction performance was conducted in the reverberation chamber. The results indicated that the reinforced ribless panel improved the transmission loss in the overall high-frequency range. Specifically, 6.7 dB of transmitted noise was reduced using the new panel suggested in this research.
Introduction. Onboarding rolling stock that exerts increased axial loads makes assessing wheels force impact on railway tracks more acute and relevant. Specialist literature describes many techniques for measuring lateral forces and lateral wear with varying degrees of accuracy. However, the questions of the correct position of measuring devices along the circular segments of a curve, spacing and frequency of measuring force parameters during the service life of the track rails are still open. The article discusses the impact of 25 tf open-box cars on the load and wear of the trackways in curves that have different radii.Materials and methods. In order to analyse and detail the total load exerted by each car wheel on track rails on the second main track of the Slyudyanskaya Division, East Siberian Infrastructure Directorate (descending segment), the authors selected two (R298 and R565 m) curved segments with almost identical slopes and comparable operating parameters. Tests were carried out to measure the load exerted on the rails along two trial segments of the track and also measurement trips of Sprinter-Integral, an infrastructure diagnostic complex (by Firma TVEMA JSC), were made along the trial curve.Results. The researchers processed and analysed the data obtained for open-box cars with an axial load of 25 tf (245.3 kN). It has been established that of all the wheels that passed along the R298 m curve, 58% impacted the inner rail in an outward direction from the rail track with 42% having an inward impact. The inner rail is exposed to an average lateral force of 37.9 kN directed outward and 30.9 kN directed inward. Similar data is obtained for the R565 m curve. A comparison of the diagrams of lateral wear and lateral forces obtained for both curves showed that changes in them occurred synchronically.Discussion and conclusion. In order to comprehensively analyse wheels impact, it is necessary to assess the impact from lateral forces which is especially important for curved track.
Abstract Rolling stock manufacturers are finding structural solutions to reduce power required by the vehicles, and the lightweight design of the car body represents a possible solution. Optimization processes and innovative materials can be combined in order to achieve this goal. In this framework, we propose the redesign and optimization process of the car body roof for a light rail vehicle, introducing a sandwich structure. Bonded joint was used as a fastening system. The project was carried out on a single car of a modern tram platform. This preliminary numerical work was developed in two main steps: redesign of the car body structure and optimization of the innovated system. Objective of the process was the mass reduction of the whole metallic structure, while the constraint condition was imposed on the first frequency of vibration of the system. The effect of introducing a sandwich panel within the roof assembly was evaluated, focusing on the mechanical and dynamic performances of the whole car body. A mass saving of 63% on the optimized components was achieved, corresponding to a 7.6% if compared to the complete car body shell. In addition, a positive increasing of 17.7% on the first frequency of vibration was observed. Encouraging results have been achieved in terms of weight reduction and mechanical behaviour of the innovated car body.
Accurate positioning of trains is of great importance to the safety of train operation. In some foreign subway projects, limited by the maturity of technical system and control of design cost, conventional GPS and CBTC positioning technologies cannot meet the demand of train positioning in the projects. Therefore, a nonlinear compensation based self-positioning method for rail transit trains is proposed. This method can achieve precise positioning of trains solely relying on existing onboard equipment without adding new equipment such as GPS, CBTC, etc. The proposed method features simple composition, low cost, high accuracy, and high reliability (free from environmental affection), which is worth further promotion. Firstly, the specific process used neural networks to establish a compensation model for the instantaneous speed of trains and improve the accuracy of train instantaneous speed through the compensation model, and then the real-time running distance of the train was obtained by integrating the compensated real-time speed and operating time of the train. Afterwards, the distance of the train to the next station was calculated based on the fixed train operation diagram, thus to realize positioning. The experimental results show that after compensation the positioning accuracy is less than 0.2 m, upgraded by 3-4 times of the accuracy before compensation.
Sedimentation is one of the main eco-morphological and technological challenges associated with reservoirs. Sedimentation not only reduces the functional capacity of a reservoir by filling it, but also changes downstream sediment dynamics and habitat availability for the aquatic biota. Additionally, dams hinder free bi-directional fish passage, emerging as a major threat to species of migratory fish. In the past decades, mitigation measures aimed at reducing such environmental and technological impacts have been developed. Sediment bypass tunnels (SBTs) have been shown to successfully help prevent reservoir sedimentation, whereas fish passages have been found to be potential solutions to facilitate bi-directional passage of fish. However, the construction of such structures, in particular of SBT, can be extremely costly. The development of design solutions that can function both for downstream sediment transport and up- and downstream fish passage should be considered as they can mitigate ecological deficiencies of reservoir operations while accounting for economic feasibility. Possibilities and challenges of combining SBT and fish passage were explored by bringing together a team of interdisciplinary specialists on hydraulics, sediment transport and continuity, bypassing, hydraulic structures, hydropower engineering, aquatic biology, and fish passage in a two-day workshop. Here, we present potential solutions identified during the workshop for integrating SBT and fish passage.
E. N. Efimova, N. P. Vinogorov, A. A. Shiladzhyan
et al.
Introduction. The article covers the approaches to assessing the efficient functioning of the modern upper structure track and aims at developing these approaches in the process of using the track superstructure materials — rails, fasteners, sleepers, ballast — under given operating conditions.Materials and methods. The authors proposed methodological approaches for assessing the effective functioning of the modern upper structure track. These methods were based on the life cycle cost measurements of railway complex technical systems. The methodological approaches enable to consider the expenditures for the acquisition, possession and disposal of the upper structure track materials by discounting the cost indicators and the initial period value.Results. The authors present the results of test calculations for assessing the effective use of ZhBR-65PShM, ZhBR-65Sh, ARS-4, Vossloh W-30 rail fasteners types on a 12-kilometer nominal section of the continuous welded rail with DT350 rails and a traffic density up to 80 t.km gross/km per year. The most efficient upper structure track option is the one, which has the lowest value of unit costs per 1 t.km gross and covers the full life cycle of the railway track section operation.Discussion and conclusion. The developed methodological approaches will be used to evaluate, compare and select the most efficient upper structure track schemes under given operating conditions.
This paper presents electrical power system comprises many complex and interrelating elements that are susceptible to the disturbance or electrical fault. The faults in electrical power system transmission line (TL) are detected and classified. But, the existing techniques like Artificial Neural Network (ANN) failed to improve the Fault Detection (FD) performance during transmission and distribution. In order to reduce the Power Loss Rate (PLR), Daubechies Wavelet Transform based Gradient Ascent Deep Neural Learning (DWT-GADNL) Technique is introduced for FDin electrical power sub-station. DWT-GADNL Technique comprises three step, normalization, feature extraction and FD through optimization. Initially sample power TL signal is taken. After that in first step, min-max normalization process is carried out to estimate the various rated values of transmission lines. Then in second step, Daubechies Wavelet Transform (DWT) is employed for decomposition of normalized TL signal to different components for feature extraction with higher accuracy. Finally in third step, Gradient Ascent Deep Neural Learning is an optimization process for detecting the local maximum (i.e., fault) from the extracted values with help of error function and weight value. When maximum error with low weight value is identified, the fault is detected with lesser time consumption. DWT-GADNL Technique is measured with PLR, Feature Extraction Accuracy (FEA), and Fault Detection Time (FDT). The simulation result shows that DWT-GADNL Technique is able to improve the performance of FEA and reduces FDT and PLR during the transmission and distribution when compared to state-ofthe- art works. An electric power system incorporates production, broadcast and distribution of electric energy. To send the electric power to massive load centers, transmission lines are exploited. The fast growth of electric power systems results in huge number of lines in operation and total length. TL are susceptible to faults in case of lightning, short circuits, mis-operation, human errors, overload, etc. Faults resulted in tiny to long power outages for customers. To protect the reliable power system operations, Fault identification, isolation and localization are imperative. The voltage lessened to minimal value, when fault occurs on TL. FD is an essential problem in power system engineering to minimize the PLR. DWT-GADNL Technique is introduced for FD in TL during transmission and distribution. Power Loss due to the fault occurrence during the transmission and distribution is a common problem in electrical power system. To lessen the PLR, the fault is detected in earlier stage. From the sample transmission line, the features are extracted and the values are calculated. When the observed value is lesser than the actual value, the fault is detected through performing the gradient ascent optimization process in transmission line. In this optimization process, the local maxima are identified to reduce the PLR. At different time instances, PLR gets changed. At instance 3, the PLR of proposed DWTGADNL framework is 12% where the PLR of Fuzzy Logic Based Algorithm and Fault Diagnosis Framework are 27% and 19% respectively. Through comparing all the ten instances, PLR is reduced in GWMD-DE technique by 59% and 40% compared to existing respectively. DWT-GADNL Technique is introduced for FD during transmission and distribution with minimal PLR. Sample power TL signal is taken and min-max normalization process performs the various rated values estimation of transmission lines. DWT decomposes normalized TL signal to different components for feature extraction with higher accuracy. Gradient Ascent Deep Neural Learning detects the local maximum from extracted values with help of error function and weight value. When maximum error with low weight value is identified, the fault is detected with lesser time consumption. The performance of DWT-GADNL technique is tested with the metrics such as PLR, FEA and FDT. With the simulations conducted for all techniques, the proposed DWT-GADNL technique presents better performance on FD during transmission and distribution as evaluated to state-of-the-art works. From simulations results, the DWT-GADNL technique lessens PLR by 50% and enhances FEA by 9% than the existing methods.
V . K o v a l c h u k Doctor of Technical Sciences, Аssociate professor* E-mail: kovalchuk.diit@gmail.com I . K r a v e t s Postgraduate Student* Department of Bridges and Tunnels Dnipro National University of Railway Transport named after academician V. Lazaryan Lazaryan str., 2, Dnipro, Ukraine, 49010 E-mail: kravetsivan2017@gmail.com O . N a b o c h e n k o PhD, Associate Professor Department of "The rolling stock and track" Lviv Branch of Dnipro National University of Railway Transport named after Academician V. Lazaryan I. Blazhkevych str., 12a, Lviv, Ukraine, 79052 E-mail: olganabochenko@gmail.com A . O n y s h c h e n k o Doctor of Technical Sciences, Associate Professor* E-mail: onyshchenko.a.m.ntu@gmail.com O . F e d o r e n k o Acting General Director, Deputy General Director for Production Development Kyivavtodor Municipal Corporation Petra Bolbochana str., 6, Kyiv, Ukraine, 01014 E-mail: oleksandr.fedorenko.ntu@gmail.com A . P e n t s a k PhD, Associate Professor** E-mail: apentsak1963@gmail.com O . P e t r e n k o PhD, Associate Professor** E-mail: olexapetrenko@gmail.com N . H e m b a r a PhD Department of Engineering Ukrainian Academy of printing Pidholosko str., 19, Lviv, Ukraine, 79020 E-mail: gembara2011@gmail.com *Department of Bridges and Tunnels National Transport University M. Omelianovycha-Pavlenka str., 1, Kyiv, Ukraine, 01010 **Department of Construction industry National University Lviv Polytechnic S. Bandery str., 12, Lviv, Ukraine, 79013 This paper reports the analysis of the methods for estimating the technical condition of the subgrade underneath a constructed railroad track or road during its operation. The study results have proven that the issue related to monitoring and controlling high-quality compaction of a heterogeneous subgrade remains relevant and requires the construction of reliable experimental methods for assessing the subgrade degree of compaction. A procedure for determining the compaction of subgrade in the laboratory has been devised, based on inertial microcomputer technologies, which makes it possible to assess the degree of compaction of subgrade soils depending on the propagation rate of an impact's elastic waves. An experimental study has been performed into the propagation rate of elastic waves across a homogeneous subgrade made of coarse-grained sand and a heterogeneous subgrade made of coarse sand with a layer of clay in the middle of the prism. The study results established that the propagation rate of an elastic wave in a heterogeneous subgrade accepts a lower value than the rate of wave propagation in a homogeneous subgrade. Through the dynamic interpretation, by using a discriminant statistical analysis, the characteristic features have been defined in the distribution of accelerations in the body of the homogeneous and heterogeneous subgrade, depending on the degree of compaction, which would make it possible to monitor the state of the subgrade during operation. As the degree of the subgrade soil compaction affects the technical condition of roads
With the advancement of electronic power technology, power devices are constantly developing towards high power density and high integration. The interconnect layer, as a key channel for heat transfer in power modules, has an important impact on the realization of high-temperature and reliable applications of power modules. Low-temperature sintered silver has become one of the research focus on packaging interconnect materials due to its excellent characteristics such as low process temperature, high interconnect strength, high operating temperature, high electrical conductivity, and high thermal conductivity. However, the high sintering driving force requirement, low sintering density, and high thermal-mechanical stress limit the wide application of low temperature sintered silver technology in the field of large-area package interconnects. The existing research methods and results from the material and process viewpoints were summarized and compared, and the research focus and development direction of low-temperature sintered silver packaging interconnect technology were proposed, which was important for expanding the application of low-temperature sintered silver technology.
Abstract: A significant change was introduced to the legislation regulating the state-owned enterprises in the last decade of the 20th century. The change made it possible to transfer companies under control of different managerial entities on the basis of the so-called management contracts. In the following paper the author will give an account of the practices related to management contracts as concluded by the Ministry of Transport during the relevant period. Keywords: State-owned enterprise; Management contract; Transport
Highway engineering. Roads and pavements, Bridge engineering
Subsea Wellheads are the male part of an 18 3/4” bore connector used for connecting subsea components such as drilling BOP, XT or Workover systems equipped with a female counterpart — a wellhead connector. Subsea wellheads have an external locking profile for engaging a preloaded wellhead connector with matching internal profile. As such connection is made subsea, a metal-to-metal sealing is obtained, and a structural conduit is formed. The details of the subsea wellhead profile are specified by the wellhead user and the standardized H4 hub has a widespread use. In terms of well integrity, the wellhead connector is a barrier element during both well construction (drilling) activities and life of field (production). Due to the nature of subsea drilling operations, a wellhead connector will be subjected to external loads. Fatigue and plastic collapse due to overload are therefore two potential failure modes. These two failure modes are due to the cyclic nature of the loads and the potential for accidental and extreme single loads respectively. The safe load the wellhead connector can sustain without failure can be established by deterministic structural capacity methods. This paper outlines how a generic and probabilistic engineering method; Structural Reliability Analysis, can be applied to a subsea wellhead connector to estimate the probability of fatigue failure (PoF). As the wellhead connector is a mechanism consisting of a plurality of parts the load effect from cyclic external loads is influenced by uncertainty in friction, geometry and pre-load. Further, there is a inter dependence between these parameters that complicates the problem. In addition to these uncertainties, uncertainties in the fatigue loading itself (from rig and riser) is also accounted for. This paper presents results from applications of Structural Reliability Analysis (SRA) to a wellhead connector and provides experiences and learnings from this case work.
Pradeep MHealth For Belt And Road Region (mHBR), Mingzhong Wang, Chongdan Pan
BACKGROUND Researchers have been investigating the use of robots in the world for elderly in various types of applications, such as communication with relatives and friends at a distance, transportation of medical supplies and equipment across healthcare/aged care facilities, surgical procedures etc. In China, ground zero of the COVID-19 outbreak, robots are being used in hospitals to deliver food and medication and take patients' temperatures. Drones are deployed to transport supplies, spray disinfectants and do thermal imaging. This paper will focus on telepresence robots that have become critically important to perform remote healthcare operations, complying with social distancing measures.UNSW and University of Sunshine Coast have been partners in the European Union VictoryaHome (VH) project (2014-2016) that involved Australia and EU countries Norway, Sweden, Netherlands and Portugal. The project was aimed at better emotional health of the elderly and the project identified some major problems, such as the high cost of robot and its high complexity, making their adoption difficult. This led to the project “Robots for Elderly” as part of the new “Robots for Elderly” project (involving Australia, China, Bangladesh and EU) in mHealth for Belt and Road (mHBR) Initiative led by the UM-SJTU Joint Institute in China from 2018. OBJECTIVE The aim of this study is to design, implement and test a low-cost telepresence robot for healthcare. The focus has been on implementing a low-cost telepresence robot for healthcare management for the elderly during pandemics like COVID-19. METHODS This project uses an innovative, multi-disciplinary collaboration across disciplines (software, electronics engineering, mechatronics and public health) involving young university talents from these fields. RESULTS According to preliminary customer feedback, the main functions have already been realized by our robot. The cost is approx. $500, about 20 times less expensive than the Giraff robot used in the VH project. CONCLUSIONS Many groups all over the world have been trying to develop low-cost robots for various applications. We addressed the needs for the healthcare of elderly, most affected by the Coronavirus and came up with a simple low-cost design of telepresence robot that can be deployed widely in hospitals and aged care establishments. The system is currently in a prototype level and will require an entrepreneur to commercialize it in large scale.
Subsea Wellheads are the male part of an 18 3/4” bore connector used for connecting subsea components such as drilling BOP, XT or Workover systems equipped with a female counterpart — a wellhead connector. Subsea wellheads have an external locking profile for engaging a preloaded wellhead connector with matching internal profile. When the connector is locked subsea a metal-to-metal sealing is obtained and a structural conduit is formed. The details of the subsea wellhead profile are specified by the wellhead user and the standarisedH4 hub has a widespread use. In terms of well integrity, the wellhead connector is a barrier element during both well construction (drilling) activities and life of field (production). Due to the nature of subsea drilling operations a wellhead connector will be subjected to external loads. Fatigue and plastic collapse are therefore two potential failure modes. These two failure modes are due to the cyclic nature of the loads and the potential for accidental and extreme single loads respectively. Establishing the safe load level that the wellhead connector has structural capacity to handle without failure can be done by deterministic engineering methods. Similarly, a deterministic calculated safe fatigue life is the use limit preventing fatigue failure, assuming no inspections. Probabilistic engineering method; Structural Reliability Analysis (SRA), can be applied to a subsea wellhead connector to establish the probability of fatigue failure (PoF). Risk Based Inspection (RBI) is a probabilistic analysis procedure that requires quantified PoF and Consequence of Failure (CoF). The RBI outcome may be used to optimized inspection plans to ensure a safe PoF target level. The RBI methodology is widely accepted, and guidance can be found in several standards. Subsea wellheads are normally classified as un-inspectable. During drilling operations commencement, the uppermost section of the wellhead (high pressure housing including H4 hub profile) will be visible and accessible thus allowing for inspection. This uppermost section may also accessible for inspection when a wellhead connector is locked on. From an SRA basis a generic RBI procedure applicable to subsea wellheads are proposed and established for a generic case of a 27” mandrel with a H4 hub. This paper then proceeds to providing the maximum non detectable flaw size performance required for a wellhead inspection tool/method to be efficient. The importance of accidental load and cyclic load magnitude and uncertainty is shown to impact this conclusion. The potential inspectional value of performing BOP connector leak test at regular intervals during the drilling operation has also been investigated and shown to be conditionally limited. This paper proposes a procedure for application of RBI to the problem of achieving life extension of a wellhead external locking profile while connected to a wellhead connector. The objective is to propose minimum performance requirements for the inspection tool/method to be efficient. Finally, the potential impact of RBI results in a well integrity risk assessment is covered.
In the context of economic integration, an important factor is increasing the efficiency of rail transport. It depends both on the quality of the transportation process as a whole and on the quality of its individual elements. It is especially worth highlighting the rolling stock, and in particular freight cars, since it is with the car along the route that labor-intensive technological operations are performed, including shunting, technical and commercial maintenance, unscheduled repairs, as well as starting and finishing operations — loading and unloading. Therefore, the efficiency of freight transportation does not depend to a small extent on the quality of cars.In this regard, the article highlights the results of the development of a holistic model for the formation of requirements for freight cars that increase the efficiency of the transportation process, taking into account the features of specific transportation conditions. In this case, a holistic model is applied to the conditions for the export of freights from fields in Western Siberia along the routes of the Northern Latitudinal Railway project.A holistic model for the formation of requirements for the cars of the Northern Latitudinal Railway includes:• operational and functional model, containing the substantiation of the technical and economic parameters of the cars and the model of their operation ranges, taking into account the technological operations performed;• reliability model containing justification of the reliability indicators of cars and the parameters of the system of their maintenance and repair;• model for evaluating and confirming efficiency based on the results of calculating a complex of technical and economic indicators of cars.The holistic model makes it possible to formulate rational requirements for cars of different levels of specialization for specific operating conditions. The model also makes it possible to predict the effects of participants in the transportation process when using cars with given characteristics in specific transportation conditions. This contributes to the use of the principles of dynamic pricing of tariffs, depending not only on the type of freight and the region, but also on the route, distance of transportation and other parameters. As a result, the advantages and competitiveness of rail transport will be provided.