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1 – 10 of 13Lichao Wang, Fuyan Ding, Dongbo Yang, Ke Wang, Biaoqiang Jiao and Qian Chen
This paper aims to provide a new method of generating relatively accurate and smooth saturated B-H curves based on reliable measurement data to improve the accuracy and efficiency…
Abstract
Purpose
This paper aims to provide a new method of generating relatively accurate and smooth saturated B-H curves based on reliable measurement data to improve the accuracy and efficiency of electromagnetic simulation.
Design/methodology/approach
The characteristics of different B-H curve extrapolation models are summarized, and an improved method is proposed. The fitting procedure in low fields and extrapolation procedure in high fields are presented in detail. The saturated B-H curves generated by various methods are compared and discussed. Finally, a simulation case study proved the advantages of the new method in terms of simulation accuracy and efficiency.
Findings
The B-H curve created by the new method avoids extrapolation from a single point and simultaneously smoothens the entire B-H curve, thereby improving the simulation accuracy and efficiency. The low magnetic potential requirements for closed measurements and the small deviation with open measurements indicate that this method is well-suited for implementation.
Research limitations/implications
The results are applicable for materials subject to such excitation levels that saturation has to be taken into account.
Originality/value
While some extrapolation models of B-H curves have been investigated in reference papers, there is still room for improvement in accuracy and smoothness. The new method processes low fields and high fields magnetization data and then connects them based on third-order boundary equations for the first time. This method can generate saturated B-H curves with good accuracy and smoothness while retaining outstanding operability.
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Dongbo Li, Jianpei Wang, Bing Yang, Yongle Hu and Ping Yang
This paper aims to perform experimental test on fatigue characteristics of package on package (POP) stacked chip assembly under thermal cycling load. Some suggestions for design…
Abstract
Purpose
This paper aims to perform experimental test on fatigue characteristics of package on package (POP) stacked chip assembly under thermal cycling load. Some suggestions for design to prolong fatigue life of POP stacked chip assembly are provided.
Design/methodology/approach
The POP stacked chip assembly which contains different package structure mode and chip position was manufactured. The fatigue characteristics of POP stacked chip assembly under thermal cycling load were tested. The fatigue load spectrum of POP stacked chip assembly under thermal cycling load was given. The fatigue life of chips can be estimated by using the creep–fatigue life prediction model based on different stress conditions.
Findings
The solder joint stress of top package is significantly less than that of bottom solder joints, and the maximum value occurs in the middle part of the solder joints inner ring.
Originality/value
This paper fulfils useful information about the thermal reliability of POP stacked chip assembly with different structure characteristics and materials parameters.
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Tian Tian, Ruibo Zhao, Dongbo Wei, Kai Yang and Pingze Zhang
The purpose of this paper is to expound the relationship among microstructure, mechanical property, tribological behavior and deformation mechanism of carburized layer deposited…
Abstract
Purpose
The purpose of this paper is to expound the relationship among microstructure, mechanical property, tribological behavior and deformation mechanism of carburized layer deposited on Ti-6Al-4V alloy by double-glow plasma hydrogen-free carburizing surface technology.
Design/methodology/approach
Morphologies and phase compositions of the carburized layer were observed by scanning electron microscope and X-ray diffraction. The micro-hardness tests were used to evaluate the surface and cross-sectional hardness of carburized layer. The reciprocating friction and wear experiments under various load conditions were implemented to investigate the tribological behavior of carburized layer. Moreover, scratch test with ramped loading pattern was carried out to illuminate the deformation mechanism of carburized layer.
Findings
Compared to substrate, the hardness of surface improved to ∼1,100 HV0.1, while the hardness profile of carburized layer presented gradual decrease from ∼1,100 to ∼300 HV0.1 within the distance of the total carburizing-affected region about 30 µm. The coefficient of friction, wear rate and wear morphology of carburized layer were analyzed. Scratch test indicated that the deformation process of carburized layer could be classified into three mechanisms (elastic, changing elastic–plastic and stable elastic–plastic mechanisms), and the deformation transition of the carburizing-affected region was from changing elastic–plastic to elastic mechanisms. Both the elastic and changing elastic–plastic mechanisms are conducive to the wearing course.
Originality/value
Using this technology, hydrogen embrittlement was avoided and wear resistance property of titanium alloy was greatly improved. Simultaneously, the constitutive relation during the whole loading process was deduced in terms of scratch approach, and the deformation mechanism of carburized layer was discussed from a novel viewpoint.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0489/
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Zesheng Wang, Dongbo Wu, Hui Wang, Jiawei Liang and Jingguang Peng
Assembly errors of aeroengine rotor must be controlled to improve the aeroengine efficiency. However, current method cannot truly reflect assembly errors of the rotor in working…
Abstract
Purpose
Assembly errors of aeroengine rotor must be controlled to improve the aeroengine efficiency. However, current method cannot truly reflect assembly errors of the rotor in working state owing to difficulties in error analysis. Therefore, the purpose of this study is to establish an optimization method for aeroengine rotor stacking assembly.
Design/methodology/approach
The assembly structure of aeroengine rotor is featured. Rotor eccentricity is optimized based on Jacobian–Torsor model. Then, an optimization method for assembly work is proposed. The assembly process of the high-pressure compressor rotor and the high-pressure turbine rotor as the rotor core assembly is mainly considered.
Findings
An aeroengine rotor is assembled to verify the method. The results show that the predicted eccentricity differed from the measured eccentricity by 6.1%, with a comprehensive error of 8.1%. Thus, the optimization method has certain significance for rotor assembly error analysis and assembly process optimization.
Originality/value
In view of the error analysis in the stacking assembly of aeroengine rotor, an innovative optimization method is proposed. The method provides a novel approach for the aeroengine rotor assembly optimization and is applicable for the assembly of high-pressure compressor rotor and high-pressure turbine rotor as the rotor core assembly.
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Geng Zhang, Qinglu Ma, Dongbo Pan, Yu Zhang, Qiaoli Huang and Shan Jiang
In an intelligent transportation system (for short, ITS) environment, a vehicle’s motion is affected by the information in a large scale. The purpose of this paper is to study the…
Abstract
Purpose
In an intelligent transportation system (for short, ITS) environment, a vehicle’s motion is affected by the information in a large scale. The purpose of this paper is to study the integration effect of multiple vehicles’ delayed velocities on traffic flow.
Design/methodology/approach
This paper constructed a new car-following model to study the integration effect of multiple vehicles’ delayed velocities on traffic flow. The new model is analyzed by linear and nonlinear perturbation method theoretically and also verified by simulation.
Findings
It is found out that the integration of preceding vehicles’ delayed velocities affect the stability of traffic flow importantly, and three preceding vehicles’ delayed velocities information should be considered in real traffic.
Originality/value
The new car-following model by considering the integration effect of multiple vehicles’ delayed velocities is firstly proposed in this paper. The research result shows that three preceding vehicles’ delayed velocities information is the best choice to stabilizing traffic flow.
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Ligang Lu, Pengfei Li, Dongbo Wu, Jiawei Liang, Hui Wang and Pengpeng He
The purpose of this study is to establish an assembly accuracy analysis model of deployable arms based on Jacobian–Torsor theory to improve the assembly accuracy. Spacecraft…
Abstract
Purpose
The purpose of this study is to establish an assembly accuracy analysis model of deployable arms based on Jacobian–Torsor theory to improve the assembly accuracy. Spacecraft deployable arm is one of the core components of spacecraft. Reducing the errors in assembly process is the main method to improve the assembly accuracy of spacecraft deployable arms.
Design/methodology/approach
First, the influence of composite connecting rod, root joint and arm joint on assembly accuracy in the tandem assembly process is analyzed to propose the assembly accuracy analysis model. Second, a non-tandem assembly process of “two joints fixed-composite rod installed-flange gasket compensated” is proposed and analyzed to improve the assembly accuracy of deployable arms. Finally, the feasibility of non-tandem assembly process strategy is verified by assembly experiment.
Findings
The experiential results show that the assembly errors are reduced compared with the tandem assembly process. The errors on axes x, y and z directions decreased from 14.1009 mm, 14.2424 mm and 0.8414 mm to 0.922 mm, 0.671 mm and 0.2393 mm, respectively. The errors round axes x and y directions also decreased from 0.0050° and 0.0053° to 0.00292° and 0.00251°, respectively.
Originality/value
This paper presents an assembly accuracy analysis model of deployable arms and applies the model to calculate assembly errors in tandem assembly process. In addition, a non-tandem assembly process is proposed based on the model. The experimental results show that the non-tandem assembly process can improve the assembly accuracy of deployable arms.
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Jianfeng Zhao, Bodong Liang and Qiuxia Chen
The successful and commercial use of self-driving/driverless/unmanned/automated car will make human life easier. The paper aims to discuss this issue.
Abstract
Purpose
The successful and commercial use of self-driving/driverless/unmanned/automated car will make human life easier. The paper aims to discuss this issue.
Design/methodology/approach
This paper reviews the key technology of a self-driving car. In this paper, the four key technologies in self-driving car, namely, car navigation system, path planning, environment perception and car control, are addressed and surveyed. The main research institutions and groups in different countries are summarized. Finally, the debates of self-driving car are discussed and the development trend of self-driving car is predicted.
Findings
This paper analyzes the key technology of self-driving car and illuminates the state-of-art of the self-driving car.
Originality/value
The main research contents and key technology have been introduced. The research progress as well as the research institution has been summarized.
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Yifei Tong, Ruiwen Zhao, Wei Ye and Dongbo Li
Crane plays a very important role in national economy with greatly reduced labor intensity, improved production efficiency and promoted social development as an indispensable…
Abstract
Purpose
Crane plays a very important role in national economy with greatly reduced labor intensity, improved production efficiency and promoted social development as an indispensable auxiliary tool and process equipment. Therefore, its energy consumption becomes an unavoidable topic and in fact, energy consumption of crane is very huge. It has been proved to be the most cost-effective way for reducing energy consumption to establish and implement new energy efficiency standard. Thus, it is necessary to analyze and evaluate the energy efficiency for overhead crane so as to propose a new energy efficiency standard. The paper aims to discuss these issues.
Design/methodology/approach
In this paper, four kinds of energy consumption sources of overhead crane is considered, based on which, an energy efficiency grading model for overhead crane based on BP neural network is proposed. Second, DS evidential theory is analyzed and based on it, an energy efficiency evaluation model based on BP neural network and DS evidential theory is proposed. The evaluation procedure is discussed in detail. Then, a case is demonstrated how the evaluation is carried out.
Findings
If overhead cranes with different energy consumptions need to be graded according to energy efficiency, the criterions to establish the energy efficiency labels for overhead cranes is proposed in this paper.
Practical implications
The research results can provide energy efficiency standard proposal of overhead crane for relative departments to monitor the design, manufacturing and use of overhead crane.
Originality/value
An energy efficiency grading model for overhead crane based on BP neural network is proposed. An energy efficiency evaluation model based on BP neural network and DS evidential theory is proposed.
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Ho Pham Huy Anh and Cao Van Kien
The purpose of this paper is to propose an optimal energy management (OEM) method using intelligent optimization techniques applied to implement an optimally hybrid heat and power…
Abstract
Purpose
The purpose of this paper is to propose an optimal energy management (OEM) method using intelligent optimization techniques applied to implement an optimally hybrid heat and power isolated microgrid. The microgrid investigated combines renewable and conventional power generation.
Design/methodology/approach
Five bio-inspired optimization methods include an advanced proposed multi-objective particle swarm optimization (MOPSO) approach which is comparatively applied for OEM of the implemented microgrid with other bio-inspired optimization approaches via their comparative simulation results.
Findings
Optimal multi-objective solutions through Pareto front demonstrate that the advanced proposed MOPSO method performs quite better in comparison with other meta-heuristic optimization methods. Moreover, the proposed MOPSO is successfully applied to perform 24-h OEM microgrid. The simulation results also display the merits of the real time optimization along with the arbitrary of users’ selection as to satisfy their power requirement.
Originality/value
This paper focuses on the OEM of a designed microgrid using a newly proposed modified MOPSO algorithm. Optimal multi-objective solutions through Pareto front demonstrate that the advanced proposed MOPSO method performs quite better in comparison with other meta-heuristic optimization approaches.
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Davy Preuveneers, Wouter Joosen and Elisabeth Ilie-Zudor
Industry 4.0 envisions a future of networked production where interconnected machines and business processes running in the cloud will communicate with one another to optimize…
Abstract
Purpose
Industry 4.0 envisions a future of networked production where interconnected machines and business processes running in the cloud will communicate with one another to optimize production and enable more efficient and sustainable individualized/mass manufacturing. However, the openness and process transparency of networked production in hyperconnected manufacturing enterprises pose severe cyber-security threats and information security challenges that need to be dealt with. The paper aims to discuss these issues.
Design/methodology/approach
This paper presents a distributed trust model and middleware for collaborative and decentralized access control to guarantee data transparency, integrity, authenticity and authorization of dataflow-oriented Industry 4.0 processes.
Findings
The results of a performance study indicate that private blockchains are capable of securing IoT-enabled dataflow-oriented networked production processes across the trust boundaries of the Industry 4.0 manufacturing enterprise.
Originality/value
This paper contributes a decentralized identity and relationship management for users, sensors, actuators, gateways and cloud services to support processes that cross the trust boundaries of the manufacturing enterprise, while offering protection against malicious adversaries gaining unauthorized access to systems, services and information.
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