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Article
Publication date: 9 December 2019

Jianping Ma, Lianfa Yang, Yulin He and Jian Guo

This paper aims to study frictional characteristics of thin-walled tubes in the liquid impact forming (LIF) process.

Abstract

Purpose

This paper aims to study frictional characteristics of thin-walled tubes in the liquid impact forming (LIF) process.

Design/methodology/approach

LIF experiments under various impacting velocities were performed on SUS304 stainless steel tubes with various guiding lengths on a custom-designed measurement system to investigate the effects of impacting velocity and guiding length on the coefficient of friction (COF) in the guiding zone.

Findings

The results indicate that the COF changes dynamically in the guiding zone and decreases with the deformation process. The reduction range of the COF is wider in LIF than in both the conventional and pulsating hydroforming (THF), which may be contributed to the impacting velocities in a short time. Moreover, the COF decreases faster in the first half of the LIF process than in the second half. Under different impacting velocities and guiding lengths, the decreasing rate of the COF in the first half is more sensitive and obvious than that in the second half.

Originality/value

A method for determining the COF in the guiding zone in LIF is proposed and the frictional characteristics in LIF are studied. Comparing the COF of tubes in conventional THF, pulsating THF and the LIF process is valuable for improving and predicting the tubular formability in various hydraulic environments for industrial production.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0269

Details

Industrial Lubrication and Tribology, vol. 72 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 18 April 2017

Cheng-Ta Yang, Her-Tyan Yeh, Bing-Chang Chen and Guo-Xiang Jian

Extensive efforts have been conducted on the real-time strategy (RTS) games. The purpose of this paper is the specific artificial intelligence (AI) challenges posed by RTS…

Abstract

Purpose

Extensive efforts have been conducted on the real-time strategy (RTS) games. The purpose of this paper is the specific artificial intelligence (AI) challenges posed by RTS games; non-player character (NPC) is started out by collecting game-map resources to build up defenses and attack forces, to upgrade combat deployment.

Design/methodology/approach

The authors used weak AI fuzzy theory as the foundation for tunable development. With the fuzzy theory, the AI was more humanistic in its judgment process.

Findings

Well-developed AIs have been used brilliantly in various aspects in RTS games, especially in those developed by large production teams. For small production teams, how to develop an AI system in less time and at a lower cost is extremely important.

Research limitations/implication

This study aimed to develop a system using player unit threat levels for NPC deployment and arrangement so that the further strategy would be adopted for NPCs in response to player actions.

Originality/value

The RTS games would become more challenging for players to play.

Details

Engineering Computations, vol. 34 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 15 January 2019

Jun Wang, Zili Li, Gan Cui, JianGuo Liu, Chuanping Kong, Long Wang, Ge Gao and Jian Guo

The purpose of this paper is to study the corrosion behaviors of X70 steel under direct current (DC) interference at 0-1,200 A/m2 in simulated soil solution.

Abstract

Purpose

The purpose of this paper is to study the corrosion behaviors of X70 steel under direct current (DC) interference at 0-1,200 A/m2 in simulated soil solution.

Design/methodology/approach

The Tafel polarization curves of X70 steel under DC interference were tested using electrochemical method, the corrosion rate was calculated using weight-loss method and the change in steel surface was analyzed by optical microscopy.

Findings

The results showed that E-I polarization curves under 200-1,200 A/m2 interference were linear; with an increase in the DC density, the corrosion potential of X70 steel shifted positively, solution pH after the weight-loss tests increased and corrosion rate increased linearly. A mathematical relationship between polarization resistance Rp and current density was established. Corrosion morphology indicated that pitting corrosion and crevice corrosion occurred on the X70 steel under DC interference in simulated soil solution.

Originality/value

All tests were conducted at a relative higher DC density (200-1,200 A/m2). The linear fitting method is proposed to fit data of Tafel polarization curves under DC interference. This study provides guidelines for safe operation of X70 steel pipelines.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 6 June 2016

Zhongcai Shao, Jian Guo and Pin Liu

The paper aims to introduce the process flow of electroless nickel (EN) plating on carbon fiber surfaces, the effect of former processing on the properties of coating and…

Abstract

Purpose

The paper aims to introduce the process flow of electroless nickel (EN) plating on carbon fiber surfaces, the effect of former processing on the properties of coating and the dynamics of the process.

Design/methodology/approach

The coated fibers were mounted in cold-setting epoxy resin, and transverse cross-section of the coated fibers were examined under an optical microscope to ascertain the thickness, uniformity and continuity of the coating over the fiber surface. The coating morphology was studied by using a scanning electron microscope (SEM). This study also determined the activation energy and electrical properties of EN coated on carbon fibers.

Findings

Activation temperatures have a greater impact on the quality of EN. At a temperature of 80°C, the EN layer prepared was uniform and compact and fully coated the carbon fibers. The optimum components of the EN plating process is NiSO4: 28 g/L; NaH2PO2: 30 g/L; NaAc: 20 g/L; Na3C6H5O7:10 g/L; C4O6H2KNa: 2 g/L; (NH4)2SO4: 18 g/L; thiourea and lead acetate: trace; operating conditions: pH = 8.5, temperature: 70°C; time: 0.5 h). The activation energy of the EN plating on carbon fiber is 12 kJ/mol, and the electrical conductivity of nickel-plated carbon fiber in 80 mL of distilled water is 16.5 μs/cm.

Originality/value

This paper determined the optimum processing conditions and the activation energy of the EN plating on carbon fiber.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 29 April 2021

Jian Guo, Junlin Chen and Yujie Xie

This paper explores the impact of both government subsidies and decision makers' loss-averse behavior on the determination of transportation build-operate-transfer (BOT…

Abstract

Purpose

This paper explores the impact of both government subsidies and decision makers' loss-averse behavior on the determination of transportation build-operate-transfer (BOT) concession periods based on cumulative prospect theory (CPT). The prospect value of a transportation project under traffic risk can be formulated according to the value function for gains and losses and the decision weight for gains and losses. As an extra income for investors, government subsidy is designed for highly risky aspects of BOT transportation projects: uncertain initial traffic volumes and fluctuating growth rates.

Design/methodology/approach

A decision-making model determining the concession period of a transportation BOT project is proposed by using the Monte-Carlo simulation method based on CPT, and the effects of risky behaviors of private investors on concession period decision making are analyzed. A subsidy method related to the internal rate-of-return (IRR) corresponding to a specific initial traffic volume and growth rate is proposed. The case of an actual BOT highway project is examined to illustrate how the method proposed can be used to determine the concession period of a transportation BOT project considering decision makers' loss-averse behavior and government subsidy. Contingency analysis is discussed to cope with possible misestimating of key factors such as initial traffic volume and cost coefficients. Sensitivity analysis is employed to investigate the impact of CPT parameters on the concession period decisions. An actual BOT case which failed to attract private capital is introduced to show the practical application. The results are then interpreted to conclude this paper.

Findings

Based on comparisons drawn between a concession period decision-making model considering the psychological behaviors of decision makers and a model not considering them, the authors conclude that the concession period based on CPT is distinctly different from that of the loss-neutral model. The concession period based on CPT is longer than the loss-neutral concession period. That is, loss-averse private investors tend to ask for long concession periods to make up for losses they will face in the future. Government subsidies serve as extra income for investors, allowing appointed profits to be secured sooner. For the benefit side of contingency variables, the normal state of initial traffic volume, average annual traffic growth rate and bias degree and the government subsidy need to be paid close attention during the project life span. For the cost side of contingency variables, the annual operating cost variable has a significant impact on the length of predicted concession period, while the large-scale cost variable has minor impact.

Originality/value

With an actual BOT highway project, the determination of transportation BOT concession periods based on the psychological behaviors of decision makers is analyzed in this paper. As the psychological behaviors of decision makers heavily impact the decision-making process, the authors analyze their impacts on concession period decision making. Government subsidy is specifically designed for various states of initial traffic volume and fluctuating growth rates to cope with corresponding high risks and mitigate private investors' loss-averse behaviors. Contingency analysis and sensitivity analysis are discussed as the estimated values of parameters may not be authentic in actual situations.

Details

Engineering, Construction and Architectural Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0969-9988

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Article
Publication date: 2 August 2018

Hao-bo Zhang, Hui Chen, Xiao-ning Shi, Xiong Liu and Guo-jian Duan

The purpose of this paper is to study the influence of alkyl chain length and kind of anions of ionic liquids on the tribological properties with different materials as…

Abstract

Purpose

The purpose of this paper is to study the influence of alkyl chain length and kind of anions of ionic liquids on the tribological properties with different materials as friction pairs (steel-aluminum, steel-copper and steel-Si3N4 ceramic).

Design/methodology/approach

Tribological properties were evaluated by an optimol-SRV-IV reciprocation friction tester with a ball-on-block configuration at room temperature and high temperature, respectively. Friction-reducing and anti-wear properties of the ionic liquids for steel/aluminum, steel/copper and steel/ceramic contacts were evaluated on the ball-on-block reciprocating UMT-2MT tribometer. The morphologies of the worn surfaces were observed by a scanning electron microscope. The chemical states of several typical elements on the worn surfaces were examined by X-ray photoelectron spectroscopy.

Findings

Both the alkyl chain length and kind of anion influence the tribological properties of ionic liquids, especially for the length of alkyl chains. With the increase of alkyl chain length, the load carrying capacity of ionic liquids is improved at both room temperature and high temperature, and the friction reducing and antiwear behaviors are also significantly enhanced.

Research limitations/implications

The paper presents potentially useful and highly efficient lubricants.

Practical implications

Owing to their good friction-reducing and wear resistance properties, these ionic liquids are promising candidates for versatile applications.

Originality/value

This work might provide a promising research direction for design and application of ionic liquids as lubricants.

Details

Industrial Lubrication and Tribology, vol. 70 no. 7
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 April 2000

JianGuo Zhang, A.B. Sharma, Yu‐De Ni and Zheng Li

The design issues on network architecture and modulation scheme that can be used to implement reliable MIL‐STD‐1773 avionics optical fiber data buses are discussed. Both…

Abstract

The design issues on network architecture and modulation scheme that can be used to implement reliable MIL‐STD‐1773 avionics optical fiber data buses are discussed. Both single‐star and multi‐star architectures are presented to such optical fiber data buses. Several network configurations based on passive and/or active coupling components are also considered, and they are compared in terms of system complexity and reliability. Moreover, three modulation schemes are presented, i.e. partial trilevel Manchester II bi‐phase coding, extended Manchester II bi‐phase coding with beginning‐stopping flags, and pseudo‐four‐ary pulse width modulation, respectively. Their use can feasibly solve the problem associated with fast identification of correct operation states of an active transmitter at the output of optical receivers.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 9 April 2018

Bin Shi, Jian Hua Guo, Xing An Cao, En Zhu Hu and Kun Hong Hu

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Abstract

Purpose

This paper aims to explore the effects of mineral diesel fuel carbon soot (MCS) and biodiesel carbon soot (BCS) on the lubrication of polyalphaolefin (PAO) and diesel fuels.

Design/methodology/approach

Two styles of carbon soot were prepared from the natural combustion of mineral diesel fuel oil (MDO) and biodiesel oil (BDO). Tribological tests were conducted on a high-frequency reciprocating rig. Friction surfaces were characterized using three-dimensional laser scanning confocal microscopy and Raman spectroscopy.

Findings

The addition of MCS and BCS to PAO could reduce friction in most cases. MCS had a negligible effect on the wear for contents not exceeding 1.0 per cent. By contrast, BCS exhibited a considerable negative influence on the wear resistance even at low contents. For diesel fuels, MCS reduced both friction and wear, whereas BCS substantially deteriorated the lubrication of BDO. MCS formed a Fe3O4/C composite lubricating film on the friction surface. BCS also entered the contact region, but it did not form an effective Fe3O4/C composite lubricating film.

Originality/value

This work compared MDO and BDO from a different perspective, i.e. the effects of their combustion carbon soot on the lubrication of lubricating oil and fuel oil. The significant negative effect of BCS on the lubrication of lubricating oil and BDO is a problem that could occur in the industrial application of BDO.

Details

Industrial Lubrication and Tribology, vol. 70 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 April 2005

Ma Juan, Chen Jian‐jun, Zhang Jianguo and Jiang Tao

The uncertainty of the interval variable is represented by interval factor, and the interval variable is described as its mean value multiplied by its interval factor…

Abstract

The uncertainty of the interval variable is represented by interval factor, and the interval variable is described as its mean value multiplied by its interval factor. Based on interval arithmetic rules, an analytical method of interval finite element for uncertain structures but not probabilistic structure or fuzzy structure is presented by combining the interval analysis with finite element method. The static analysis of truss with interval parameters under interval load is studied and the expressions of structural interval displacement response and stress response are deduced. The influences of uncertainty of one of structural parameters or load on the displacement and stress of the structure are examined through examples and some significant conclusions are obtained.

Details

Multidiscipline Modeling in Materials and Structures, vol. 1 no. 4
Type: Research Article
ISSN: 1573-6105

Keywords

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Article
Publication date: 1 December 2011

Jia Beisi and Jiang Yingying

Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance…

Abstract

Although an important facet of modernist architecture in which function plays a prominent role, building flexibility is not entirely a new concept. Its relevance transcends generations, allowing space and structure to evolve through time. This paper investigates the relationship among main building structures, infill elements, and space by studying examples in ancient Chinese architecture. It reveals the role of building owners, users, and craftsmen from a survey of historical documentation. In studying these examples, it is concluded that craftsmen in ancient China were involved not only during the construction phase but throughout the period of use as well. Thus, in select cases, the relationship between craftsmen and owners or users had been preserved for generations. Finally, this paper suggests potential strategies for the building industry and technology in the move towards sustainable development.

Details

Open House International, vol. 36 no. 4
Type: Research Article
ISSN: 0168-2601

Keywords

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