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Available. Open Access. Open Access
Article
Publication date: 30 December 2024

Ming Gao, Dongkai Li, Kun Liu, Shuliang Xu, Feng Zhao, Ben Guo, Anhui Pan, Xiao Xie and Huanre Han

The brake pipe system was an essential braking component of the railway freight trains, but the existing E-type sealing rings had problems such as insufficient low-temperature…

50

Abstract

Purpose

The brake pipe system was an essential braking component of the railway freight trains, but the existing E-type sealing rings had problems such as insufficient low-temperature resistance, poor heat stability and short service life. To address these issues, low-phenyl silicone rubber was prepared and tested, and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.

Design/methodology/approach

The low-temperature resistance and thermal stability of the prepared low-phenyl silicone rubber were studied using low-temperature tensile testing, differential scanning calorimetry, dynamic thermomechanical analysis and thermogravimetric analysis. The sealing performance of the low-phenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.

Findings

The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability. According to the finite element analysis results, the finish of the flange sealing surface and groove outer edge should be ensured, and extrusion damage should be avoided. The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments. When the sealing effect was ensured, a small compression ratio should be selected, and rubbers with hardness and elasticity less affected by temperature should be selected. The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature (RT) and −50 °C.

Originality/value

The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.

Details

Railway Sciences, vol. 4 no. 1
Type: Research Article
ISSN: 2755-0907

Keywords

Available. Open Access. Open Access
Article
Publication date: 29 May 2020

Li Cui

Bearings in electric machines often work in high speed, light load and vibration load conditions. The purpose of this paper is to find a new fatigue damage accumulation rating…

5514

Abstract

Purpose

Bearings in electric machines often work in high speed, light load and vibration load conditions. The purpose of this paper is to find a new fatigue damage accumulation rating life model of ball bearings, which is expected for calculating fatigue life of ball bearings more accurately under vibration load, especially in high speed and light load conditions.

Design/methodology/approach

A new fatigue damage accumulation rating life model of ball bearings considering time-varying vibration load is proposed. Vibration equations of rotor-bearing system are constructed and solved by Runge–Kutta method. The modified rating life and modified reference rating life model under vibration load is also proposed. Contrast of the three fatigue life models and the influence of dynamic balance level, rotating speed, preload of ball bearings on bearing’s fatigue life are analyzed.

Findings

To calculate fatigue rating life of ball bearings more accurately under vibration load, especially in high speed and light load conditions, the fatigue damage accumulation rating life model should be considered. The optimum preload has an obvious influence on fatigue rating life.

Originality/value

This paper used analytical method and model that is helpful for design of steel ball bearing in high speed, light load and vibration load conditions.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2019-0180/

Details

Industrial Lubrication and Tribology, vol. 72 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Available. Open Access. Open Access
Article
Publication date: 1 May 2023

Ai Yibo, Zhang Yuanyuan, Cui Hao and Zhang Weidong

This study aims to ensure the operation safety of high speed trains, it is necessary to carry out nondestructive monitoring of the tensile damage of the gearbox housing material…

374

Abstract

Purpose

This study aims to ensure the operation safety of high speed trains, it is necessary to carry out nondestructive monitoring of the tensile damage of the gearbox housing material in rail time, yet the traditional tests of mechanical property can hardly meet this requirement.

Design/methodology/approach

In this study the acoustic emission (AE) technology is applied in the tensile tests of the gearbox housing material of an high-speed rail (HSR) train, during which the acoustic signatures are acquired for parameter analysis. Afterward, the support vector machine (SVM) classifier is introduced to identify and classify the characteristic parameters extracted, on which basis the SVM is improved and the weighted support vector machine (WSVM) method is applied to effectively reduce the misidentification of the SVM classifier. Through the study of the law of relations between the characteristic values and the tensile life, a degradation model of the gearbox housing material amid tensile is built.

Findings

The results show that the growth rate of the logarithmic hit count of AE signals and that of logarithmic amplitude can well characterize the stage of the material tensile process, and the WSVM method can improve the classification accuracy of the imbalanced data to above 94%. The degradation model built can identify the damage occurred to the HSR gearbox housing material amid the tensile process and predict the service life remains.

Originality/value

The results of this study provide new concepts for the life prediction of tensile samples, and more further tests should be conducted to verify the conclusion of this research.

Available. Open Access. Open Access
Article
Publication date: 1 July 2019

Li Xuemei, Yun Cao, Junjie Wang, Yaoguo Dang and Yin Kedong

Research on grey systems is becoming more sophisticated, and grey relational and prediction analyses are receiving close review worldwide. Particularly, the application of grey…

3525

Abstract

Purpose

Research on grey systems is becoming more sophisticated, and grey relational and prediction analyses are receiving close review worldwide. Particularly, the application of grey systems in marine economics is gaining importance. The purpose of this paper is to summarize and review literature on grey models, providing new directions in their application in the marine economy.

Design/methodology/approach

This paper organized seminal studies on grey systems published by Chinese core journal database – CNKI, Web of Science and Elsevier from 1982 to 2018. After searching the aforementioned database for the said duration, the authors used the CiteSpace visualization tools to analyze them.

Findings

The authors sorted the studies according to their countries/regions, institutions, keywords and categories using the CiteSpace tool; analyzed current research characteristics on grey models; and discussed their possible applications in marine businesses, economy, scientific research and education, marine environment and disasters. Finally, the authors pointed out the development trend of grey models.

Originality/value

Although researches are combining grey theory with fractals, neural networks, fuzzy theory and other methods, the applications, in terms of scope, have still not met the demand. With the increasingly in-depth research in marine economics and management, international marine economic research has entered a new period of development. Grey theory will certainly attract scholars’ attention, and its role in marine economy and management will gain considerable significance.

Details

Marine Economics and Management, vol. 2 no. 2
Type: Research Article
ISSN: 2516-158X

Keywords

Available. Open Access. Open Access
Article
Publication date: 26 November 2024

Johanna Katariina Gummerus, Deirdre Mary O’Loughlin, Carol Kelleher and Catharina von Koskull

Following an interpretivist approach, the authors draw on semi-structured interviews with parents of children with autism spectrum disorder (ASD).

415

Abstract

Purpose

Following an interpretivist approach, the authors draw on semi-structured interviews with parents of children with autism spectrum disorder (ASD).

Design/methodology/approach

Responding to limited academic advancement, particularly in the context of consumers experiencing vulnerability, the aim is to deepen marketing scholars’ understanding of value co-destruction (VCD) and its under-explored relationship with consumer ill-being.

Findings

Three forms of systemic VCD mechanisms emerged: obscuring, gaslighting and siloing. Ill-being comprised material, physical, psychological and social harms, which consumers experienced individually, relationally and collectively due to VCD. Family members’ experiences of ill-being and vulnerability were deepened by service systems’ inability to recognise the individuality of their needs and provide appropriate support.

Research limitations/implications

In line with the interpretivist paradigm, the focus on families of children with ASD, while illuminating, delimits the generalisability of the findings. The authors call for further research on consumer ill-being, VCD and vulnerability in other service and marketing contexts.

Practical implications

The findings highlight the need for service system adaptability to recognise and address unstandardised needs.

Social implications

Several systemic failures of (public) service systems which manifested as VCD mechanisms are identified.

Originality/value

The overall contribution is the development of a contextually driven characterisation of both VCD and ill-being and a deeper understanding of how these are interrelated. First, VCD revealed itself as a systemic failure to access, provide or integrate resources to meet actors’ needs as manifested by the three mechanisms. Second, the authors characterise ill-being as comprising material, physical, psychological and social harms due to VCD, which are experienced individually, relationally and collectively. Finally, the authors illuminate the nature of vulnerability and delineate the entanglements between vulnerability and ill-being in a collective (e.g. family) context.

Details

European Journal of Marketing, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0309-0566

Keywords

Available. Content available
Article
Publication date: 7 March 2019

Joshua R. Muckensturm and Dave C. Longhorn

This paper introduces a new heuristic algorithm that aims to solve the military route vulnerability problem, which involves assessing the vulnerability of military cargo flowing…

1262

Abstract

Purpose

This paper introduces a new heuristic algorithm that aims to solve the military route vulnerability problem, which involves assessing the vulnerability of military cargo flowing over roads and railways subject to enemy interdiction.

Design/methodology/approach

Graph theory, a heuristic and a binary integer program are used in this paper.

Findings

This work allows transportation analysts at the United States Transportation Command to identify a relatively small number of roads or railways that, if interdicted by an enemy, could disrupt the flow of military cargo within any theater of operation.

Research limitations/implications

This research does not capture aspects of time, such as the reality that cargo requirements and enemy threats may fluctuate each day of the contingency.

Practical implications

This work provides military logistics planners and decision-makers with a vulnerability assessment of theater distribution routes, including insights into which specific roads and railways may require protection to ensure the successful delivery of cargo from ports of debarkation to final destinations.

Originality/value

This work merges network connectivity and flow characteristics with enemy threat assessments to identify militarily-useful roads and railways most vulnerable to enemy interdictions. A geographic combatant command recently used this specific research approach to support their request for rapid rail repair capability.

Details

Journal of Defense Analytics and Logistics, vol. 3 no. 1
Type: Research Article
ISSN: 2399-6439

Keywords

Available. Open Access. Open Access
Article
Publication date: 31 October 2023

Alberto Giubilini and Paolo Minetola

The purpose of this study is to evaluate the 3D printability of a multimaterial, fully self-supporting auxetic structure. This will contribute to expanding the application of…

794

Abstract

Purpose

The purpose of this study is to evaluate the 3D printability of a multimaterial, fully self-supporting auxetic structure. This will contribute to expanding the application of additive manufacturing (AM) to new products, such as automotive suspensions.

Design/methodology/approach

An experimental approach for sample fabrication on a multiextruder 3D printer and characterization by compression testing was conducted along with numerical simulations, which were used to support the design of different auxetic configurations for the jounce bumper.

Findings

The effect of stacking different auxetic cell modules was discussed, and the findings demonstrated that a one-piece printed structure has a better performance than one composed of multiple single modules stacked on top of each other.

Research limitations/implications

The quality of the 3D printing process affected the performance of the final components and reproducibility of the results. Therefore, researchers are encouraged to further study component fabrication optimization to achieve a more reliable process.

Practical implications

This research work can help improve the manufacturing and functionality of a critical element of automotive suspension systems, such as the jounce bumper, which can efficiently reduce noise, vibration and harshness by absorbing impact energy.

Originality/value

In previous research, auxetic structures for the application of jounce bumpers have already been suggested. However, to the best of the authors’ knowledge, in this work, an AM approach was used for the first time to fabricate multimaterial auxetic structures, not only by co-printing a flexible thermoplastic polymer with a stiffer one but also by continuously extruding multilevel structures of auxetic cell modules.

Details

Rapid Prototyping Journal, vol. 29 no. 11
Type: Research Article
ISSN: 1355-2546

Keywords

Available. Content available
Article
Publication date: 5 September 2023

Shiyuan Yang, Debiao Meng, Yipeng Guo, Peng Nie and Abilio M.P. de Jesus

In order to solve the problems faced by First Order Reliability Method (FORM) and First Order Saddlepoint Approximation (FOSA) in structural reliability optimization, this paper…

266

Abstract

Purpose

In order to solve the problems faced by First Order Reliability Method (FORM) and First Order Saddlepoint Approximation (FOSA) in structural reliability optimization, this paper aims to propose a new Reliability-based Design Optimization (RBDO) strategy for offshore engineering structures based on Original Probabilistic Model (OPM) decoupling strategy. The application of this innovative technique to other maritime structures has the potential to substantially improve their design process by optimizing cost and enhancing structural reliability.

Design/methodology/approach

In the strategy proposed by this paper, sequential optimization and reliability assessment method and surrogate model are used to improve the efficiency for solving RBDO. The strategy is applied to the analysis of two marine engineering structure cases of ship cargo hold structure and frame ring of underwater skirt pile gripper. The effectiveness of the method is proved by comparing the original design and the optimized results.

Findings

In this paper, the proposed new RBDO strategy is used to optimize the design of the ship cargo hold structure and the frame ring of the underwater skirt pile gripper. According to the results obtained, compared with the original design, the structure of optimization design has better reliability and stability, and reduces the risk of failure. This optimization can also better balance the relationship between performance and cost. Therefore, it is recommended for related RBDO problems in the field of marine engineering.

Originality/value

In view of the limitations of FORM and FOSA that may produce multiple MPPs for a single performance function, the new RBDO strategy proposed in this study provides valuable insights and robust methods for the optimization design of offshore engineering structures. It emphasizes the importance of combining advanced MPP search technology and integrating SORA and surrogate models to achieve more economical and reliable design.

Details

International Journal of Structural Integrity, vol. 14 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Available. Open Access. Open Access
Article
Publication date: 31 March 2019

Olapoju Olabisi Michael

This study assessed the contribution of containerization to the development of Western Ports, Lagos Nigeria. The aim was to assess the influence of containerization on some…

409

Abstract

This study assessed the contribution of containerization to the development of Western Ports, Lagos Nigeria. The aim was to assess the influence of containerization on some indices of port development such as port infrastructure development, ship turnaround time, cargo dwell time and congestion. Questionnaire was used to gather information on the contribution of containerization to change in maritime trade in the country, the influence of containerization on terminal expansion, congestion, level of investment in container port infrastructure as well as the influence of such investment on container dwell time and ship turnaround time (TAT) and the competitiveness of container terminal within Nigeria port systems and with other developed container ports of the world. Secondary data used included statistics of reports of operations of Western Ports between 2000 and 2010 as reported by NPA, as well as reports of some selected ports derived from Containerization International Year Book, which were used in this study for the sake of global reference. Summary tables and ANOVA for the analysis of the data. Results revealed a significant contribution of containerization to maritime trade relative to the ports’ annual records but with no significant influence on ship turnaround time, cargo dwell time congestion which are determinants of port productivity and competitiveness. The study concluded that Western Ports have still not reaped gains of containerization and lacking in competitiveness when compared with other developed ports of the world.

Details

Journal of International Logistics and Trade, vol. 17 no. 1
Type: Research Article
ISSN: 1738-2122

Keywords

Available. Open Access. Open Access
Article
Publication date: 10 October 2024

Yan Wang, Shibin Wei, Fei Yang, Jiyou Fei and Jianfeng Guo

This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.

145

Abstract

Purpose

This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.

Design/methodology/approach

The development of track geometry inspection equipment for high-speed comprehensive inspection train in China in the past 20 years can be divided into 3 stages. Track geometry inspection equipment 1.0 is the stage of analog signal. At the stage 1.0, the first priority is to meet the China's railways basic needs of pre-operation joint debugging, safety assessment and daily dynamic inspection, maintenance and repair after operation. Track geometry inspection equipment 2.0 is the stage of digital signal. At the stage 2.0, it is important to improve stability and reliability of track geometry inspection equipment by upgrading the hardware sensors and improving software architecture. Track geometry inspection equipment 3.0 is the stage of lightweight. At the stage 3.0, miniaturization, low power consumption, self-running and green economy are co-developing on demand.

Findings

The ability of track geometry inspection equipment for high-speed comprehensive inspection train will be expanded. The dynamic inspection of track stiffness changes will be studied under loaded and unloaded conditions in response to the track local settlement, track plate detachment and cushion plate failure. The dynamic measurement method of rail surface slope and vertical curve radius will be proposed, to reveal the changes in railway profile parameters of high-speed railways and the relationship between railway profile, track irregularity and subsidence of subgrade and bridges. The 200 m cut-off wavelength of track regularity will be researched to adapt to the operating speed of 400 km/h.

Originality/value

The research can provide new connotations and requirements of track geometry inspection equipment for high-speed comprehensive inspection train in the new railway stage.

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