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Article
Publication date: 8 February 2021

Yu Luo, Xiangdong Jiao, Zewei Fang, Shuxin Zhang, Xuan Wu, Dongyao Wang and Qin Chu

This paper aims to propose a diverless weld bead maintenance welding technology to prevent the leakage of subsea oil and gas pipeline and solve the key problems in the…

Abstract

Purpose

This paper aims to propose a diverless weld bead maintenance welding technology to prevent the leakage of subsea oil and gas pipeline and solve the key problems in the maintenance of subsea pipeline.

Design/methodology/approach

Based on the analysis of the cross-section of the fillet weld, the multi-layer and multi-pass welding path planning of the submarine pipeline sleeve fillet weld is studied, and thus a multi-layer and multi-pass welding path planning strategy is proposed. A welding seam filling method is designed, and the end position of the welding gun is planned, which provides a theoretical basis for the motion control of the maintenance system.

Findings

The trajectory planning and adjustment of multi-layer and multi-pass fillet welding and the motion stability control of the rotating mechanism are realized.

Research limitations/implications

It provides the basis for the prototype design of the submarine pipeline maintenance and welding robot system, and also lays the foundation for the in-depth research on the intelligent maintenance system of submarine pipeline.

Originality/value

The maintenance of diverless subsea pipeline is a new type of maintenance method, which can solve the problem of large amount of subsea maintenance work with high efficiency.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 2
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 7 October 2020

Liang Tian and Yu Luo

The purpose of this paper is to quantitatively investigate the effect of process parameters (including welding current, voltage and speed) and plate thickness on in-plane…

Abstract

Purpose

The purpose of this paper is to quantitatively investigate the effect of process parameters (including welding current, voltage and speed) and plate thickness on in-plane inherent deformations in typical fillet welded joint; meanwhile, the plastic strains remaining in the weld zone are also analyzed under different influencing factors.

Design/methodology/approach

To achieve the purpose of this study, a thermal-elastic-plastic finite element (TEP FE) model is developed to analyze the thermal-mechanical behavior of the T-welded joint during the welding process. Experimental measurements have verified the validity of the established TEP FE model. Using the effective model, a series of numerical experiments are performed to obtain the inherent deformations under the conditions of different influencing factors, and then the calculation results are discussed based on the relevant data obtained.

Findings

Through numerical simulation analysis, it is found that the longitudinal and transverse inherent deformations decrease with the increase of welding speed and plate thickness, whereas as the nominal heat input increases, the inherent deformations increase significantly. The longitudinal shrinkage presents a quasi-linear and nonlinear distribution in the middle and end of the weld, respectively. The plastic strains in the cross section of the T-joint also vary greatly because of the process parameters and plate thickness, but the maximum value always appears near the location of the welding toe, which means that this point faces a relatively large risk of fatigue cracking. The inherent deformations are closely related to the plastic strains remaining in the weld zone and are also affected by many influencing factors such as process parameters and plate thickness.

Research limitations/implications

In this study, relatively few influencing factors such as welding current, voltage, speed and plate thickness are considered to analyze the inherent deformations in the T-welded joint. Also, these influencing factors are all within a certain range of parameters, which shows that only limited applicability can be provided. In addition, only in-plane inherent deformations are considered in this study, without considering the other two out-of-plane components of inherent deformations.

Originality/value

This study can help to expand the understanding of the relationship between the inherent deformations and its influencing factors for a specific form of the welded joint, and can also provide basic data to supplement the inherent deformation database, thereby facilitating further researches on welding deformations for stiffened-panel structures in shipbuilding or steel bridges.

Details

Engineering Computations, vol. 38 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 2 July 2020

Yu Luo, Zewei Fang, Juzhi Guo, Hao Lu and Juan Li

This paper aims to improve the scene sense of a virtual scene, the welding model of a virtual reality system of riser automatic equipment was constructed using Unity3D and…

Abstract

Purpose

This paper aims to improve the scene sense of a virtual scene, the welding model of a virtual reality system of riser automatic equipment was constructed using Unity3D and UG software, which mainly included a welding car, welding guide rail, welding power supply, virtual camera and other equipment and the model was rendered.

Design/methodology/approach

The human-computer interaction page and simulation test of the system was produced using the user interface GUI system for creating a human-computer interaction scene. The operator could capture the welding status of the physical equipment accurately and in real-time so the virtual reality technology was very suitable for the remote monitoring operation integrated with the welding system.

Findings

Human-computer interaction design and collision detection were realized. In addition, the system simulation experiment was accomplished. With the continuous improvement and development of virtual reality technology real-time virtual simulation and monitoring, technology will become the main development trend.

Research limitations/implications

Based on virtual reality, the monitoring system can capture the operation status of physical welding equipment in real-time and accurately, which is very suitable for remote monitoring operation integrated with the welding system and also conducive to improving the monitoring level of the welding process.

Practical implications

This technology is time-saving and money-saving, for the operators do not have to be in a real welding environment and therefore they can get away from dangerous places. Consequently, it can avoid unnecessary injuries and problems.

Social implications

This technology can replace people to enter the dangerous and extreme environment to carry out welding operation, so it becomes the most effective means of nuclear power plant maintenance, space structure construction and marine engineering construction. In addition, it is time-saving and money-saving.

Originality/value

With the rapid development of virtual reality technology in recent years, it is a new research direction to apply virtual reality technology to the remote welding operation. This technology is different from the traditional way of welding for the operators can stay away from the welding scene especially some dangerous places.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

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Book part
Publication date: 30 June 2016

P. Matthijs Bal and Paul G. W. Jansen

As demographic changes impact the workplace, governments, organizations, and workers are looking for ways to sustain optimal working lives at higher ages. Workplace…

Abstract

As demographic changes impact the workplace, governments, organizations, and workers are looking for ways to sustain optimal working lives at higher ages. Workplace flexibility has been introduced as a potential way workers can have more satisfying working lives until their retirement ages. This chapter presents a critical review of the literature on workplace flexibility across the lifespan. It discusses how flexibility has been conceptualized across different disciplines, and postulates a definition that captures the joint roles of employer and employee in negotiating workplace flexibility that contributes to both employee and organization benefits. Moreover, it reviews how flexibility has been theorized and investigated in relation to older workers. The chapter ends with a future research agenda for advancing understanding of how workplace flexibility may enhance working experiences of older workers, and in particular focuses on the critical investigation of uses of flexibility in relation to older workers.

Details

Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-78635-263-7

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Article
Publication date: 8 May 2018

An Yu, Xianwu Luo, Dandan Yang and Jiajian Zhou

This paper aims to gain a clear understanding of the ventilated cavity evolution around an NACA0015 hydrofoil by using both experimental and numerical investigation.

Abstract

Purpose

This paper aims to gain a clear understanding of the ventilated cavity evolution around an NACA0015 hydrofoil by using both experimental and numerical investigation.

Design/methodology/approach

The bubble evolution around an NACA0015 hydrofoil with or without air injection was observed in a water tunnel, and the simulation was conducted using a modified turbulence model and homogeneous cavitation model.

Findings

The present simulation method can successfully predict the bubble evolutions around the NACA0015 hydrofoil with or without air injection. Air injection can alleviate the nature cavitation oscillation, and the suppression effect on nature cavitation depends on the air-entrant coefficient. It is confirmed that the air and vapor cavity have the same shedding frequency. It is seen that the air sheet closely attaches to the hydrofoil surface and is surrounded by the vapor sheet. Thus, the injected air promotes vapor growth and results in an increase in the cavity shedding frequency. Further, with a large air-entrant coefficient, the pressure fluctuation is suppressed completely.

Originality/value

The new simulation method is adopted to explore the mechanism of ventilated cavitation. The bubble evolutions with and without air injection have been comprehensively studied by experimental and numerical investigation. The effects of air injection on natural cavity oscillations and pressure fluctuations have been revealed in the present study.

Details

Engineering Computations, vol. 35 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 12 February 2018

Kangkang Yu, Ben Nanfeng Luo, Xue Feng and Jianing Liu

Supply chain flexibility is crucial for firms to respond to uncertain circumstances caused by environmental factors, such as the diversity of customer demands, problems of…

Abstract

Purpose

Supply chain flexibility is crucial for firms to respond to uncertain circumstances caused by environmental factors, such as the diversity of customer demands, problems of product safety, and adjustments of industrial policies. To investigate the approach to enhance supply chain flexibility, the purpose of this paper is to propose that both internal and external information integration contribute to reactive and proactive supply chain flexibilities, which elicit high operational performance.

Design/methodology/approach

Using a sample of 84 food companies that have been listed three years in China and content analysis based on their annual reports, evidence was collected to test the hypotheses through hierarchical regressions.

Findings

The results reveal that external information integration results in both reactive and proactive flexibilities, which further improve operational performance. Internal information integration positively affects both reactive and proactive flexibilities, but its mediating role was not determined in the study.

Originality/value

The research provides insights into how supply chain flexibility mediates the effect of supply chain information integration on operational performance in the context of the Chinese food industry.

Details

The International Journal of Logistics Management, vol. 29 no. 1
Type: Research Article
ISSN: 0957-4093

Keywords

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Article
Publication date: 23 November 2007

George O. White, Janice R.W. Joplin and M. Feras Salama

The purpose of this paper is to develop a theory based on transaction cost economics to help explain how firms venturing into different foreign markets should properly…

Abstract

Purpose

The purpose of this paper is to develop a theory based on transaction cost economics to help explain how firms venturing into different foreign markets should properly formulate and implement contractual governance mechanisms to create greater efficiency, lower costs, and minimize conflict with partners.

Design/methodology/approach

Defines and discusses a conceptual framework of the determinants regarding contracts and strategies used to manage conflict in foreign ventures through the integration of foreign venture conflict resolution, contract, and transaction cost economics literature.

Findings

Suggests that perceived transaction costs will predict which contractual governance mechanism and which conflict resolution strategy a partner firm will choose when resolving conflict in a foreign venture. Postulates that consistency of conflict resolution strategy with contract type will impact the performance of the foreign venture, and that cultural distance, relative power, and interest alignment will all play a moderating role in this process.

Originality/value

The model demonstrates the necessity of examining how coupling certain conflict resolution strategies and contract types will impact foreign venture performance.

Details

International Journal of Conflict Management, vol. 18 no. 4
Type: Research Article
ISSN: 1044-4068

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Article
Publication date: 1 October 2018

Kaiwen Pang, Yaojun Li, Wei Yang and Zhuqing Liu

This study aims to develop and validate a new cavitation model that considers thermodynamic effects for high-temperature water flows.

Abstract

Purpose

This study aims to develop and validate a new cavitation model that considers thermodynamic effects for high-temperature water flows.

Design/methodology/approach

The Rayleigh–Plesset equation and “B-factor” method proposed by Franc are used to construct a new cavitation model called “thermodynamic Zwarte–Gerbere–Belamri” (TZGB) by introducing the thermodynamic effects into the original ZGB model. Furthermore, the viscous term of the Rayleigh–Plesset equation is considered in the TZGB model, and the model coefficients are formulated as a function of temperature. Cavitating flows around the NACA0015 hydrofoil under different water temperatures (25°C, 50°C and 70°C) at the angle of attack of 5° are calculated.

Findings

Results of the investigated temperatures show good agreement with the available experimental data. Given that the thermodynamic and viscosity effects are included in the TZGB model and the model coefficients are treated as a function of temperature, the TZGB model shows better performance in predicting the pressure coefficient distribution and length of cavity than the original ZGB cavitation model and other models do. The TZGB model aims to determine the thermodynamic and viscosity effects and perform better than the other models in predicting the mass transfer rate, particularly in high-temperature water.

Originality/value

The TZGB model shows potential in predicting the cavitating flows at high temperature and the computational cost of this model is similar to that of the original ZGB model.

Details

Engineering Computations, vol. 35 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 4 February 2020

Ashkan Ayough, Mohammad Hosseinzadeh and Alireza Motameni

Line–cell conversion and rotation of operators between cells are common in lean production systems. Thus, the purpose of this study is to provide an integrated look at…

Abstract

Purpose

Line–cell conversion and rotation of operators between cells are common in lean production systems. Thus, the purpose of this study is to provide an integrated look at these two practices through integrating job rotation scheduling and line-cell conversion problems, as well as investigating the effect of rotation frequency on flow time of a Seru system.

Design/methodology/approach

First, a nonlinear integer programming model of job rotation scheduling problem and line–cell conversion problem (Seru-JRSP) was presented. Then, because Seru-JRSP is NP-hard, an efficient and effective invasive weed optimization (IWO) algorithm was developed. Exploration process of IWO was enhanced by enforcing two shake mechanisms.

Findings

Computations of various sample problems showed shorter flow time and less number of assigned operators in a Seru system scheduled through job rotation. Also, nonlinear behavior of flow time versus number of rotation periods was shown. It was demonstrated that, setting number of rotation frequency to one in line with the literature leads to inferior flow time. In addition, ability of developed algorithm to generate clusters of equivalent solutions in terms of flow time was shown.

Originality/value

In this research, integration of job rotation scheduling and line–cell conversion problems was introduced, considering lack of an integrated look at these two practices in the literature. In addition, a new improved IWO equipped with shake enforcement was introduced.

Details

Assembly Automation, vol. 40 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 13 August 2018

Yen-Han Lee, Timothy Chiang, Mack Shelley and Ching-Ti Liu

The Chinese society has embraced rapid social reforms since the late twentieth century, including educational and healthcare systems. The Chinese Central Government…

Abstract

Purpose

The Chinese society has embraced rapid social reforms since the late twentieth century, including educational and healthcare systems. The Chinese Central Government launched an ambitious health reform program in 2009 to improve service quality and provide affordable health services, regardless of individual socio-economic status. Currently, the Chinese social health insurance includes Urban Employee Basic Medical Insurance, Urban Resident Basic Medical Insurance, and New Cooperative Medical Insurance for rural residents. The purpose of this paper is to measure the association between individual education level and China’s social health insurance scheme following the reform.

Design/methodology/approach

Using the latest (2011) China Health and Nutrition Survey (CHNS) data and multivariable logistic regression models with cross-sectional design (n=11,960), the odds ratios (OR) and 95% confidence intervals (95% CI) are reported.

Findings

The authors found that education is associated with all social health insurance schemes in China after the reform (p<0.001). Residents with higher educational attainments, such as technical school (OR: 6.64, 95% CI: 5.44–8.13) or university and above (OR: 9.86, 95% CI: 8.14–11.96), are associated with UEBMI, compared with lower-educated individuals.

Practical implications

The Chinese Central Government announced a plan to combine all social health insurance schemes by 2020, except UEBMI, a plan with the most comprehensive financial package. Further research is needed to investigate potential disparities after unification. Policy makers should continue to evaluate China’s universal health coverage and social disparity.

Originality/value

This study is the first to investigate the association between residents’ educational attainment and three social health insurance schemes following the 2009 health reform. The authors suggest that educational attainment is still associated with each social health insurance coverage after the ambitious health reform.

Details

International Journal of Health Care Quality Assurance, vol. 31 no. 7
Type: Research Article
ISSN: 0952-6862

Keywords

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