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Predicting of the Residual Resource of Car Assemblies
Ivanov Vladimir,
Vigerina Tatyana,
Pilipenko Stanislav
Issue:
Volume 5, Issue 4, December 2019
Pages:
68-73
Received:
13 February 2019
Accepted:
12 April 2019
Published:
26 October 2019
Abstract: The research paper introduces a method that can be used for the forecasting the residual life of automobile aggregates (through the example of automobile engines). The results of a test-drive have shown that the proposed method is less labor intensive and has a satisfactory forecast accuracy. In the research the tenets of the reliability theory and mathematical statistics were used as well as information on the post-repair operating time of repaired engines based on the value of the initial main parameter (the gap between the piston and cylinder) for 41 engines. The probability density of this parameter follows the Gauss’ law. In our work we accept the nonlinear change in the mathematical expectation of the main parameter depending on the operating time in the form of a power law. The probability density of the aggregate resource is distributed according to the Weibull law. Adequacy of theoretical information to experimental data was determined by the Fisher criterion. The forecasting of the residual life of the aggregates is relevant when the operating time approaches their limit state. The relative forecast error varies from 0.021 to 0.130, which is quite acceptable for the real-world applications.
Abstract: The research paper introduces a method that can be used for the forecasting the residual life of automobile aggregates (through the example of automobile engines). The results of a test-drive have shown that the proposed method is less labor intensive and has a satisfactory forecast accuracy. In the research the tenets of the reliability theory and...
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Gaining Competitive Advantage at Sea: An Overview of Shipping Lines’ Strategic Decisions
Enrico D’agostini,
Hyung-Sik Nam,
Seog-Hwan Kang
Issue:
Volume 5, Issue 4, December 2019
Pages:
74-81
Received:
4 October 2019
Accepted:
24 October 2019
Published:
31 October 2019
Abstract: The liner shipping sector has significantly changed in recent years. Largest shipping lines have expanded their business scope becoming global carriers and a recent wave of industry consolidation has profoundly modified the market structure and, consequently, the business models followed by liners. This, coupled with weak market fundamentals, generally poor balance sheets, and ordering of increasingly larger container vessels, has led each shipping line to follow a specific dominant strategy aimed at increasing market shares, margins and creating value for costumers. This article proposes an overview of the main market strategies pursued by the largest shipping lines. Through an analysis of major container lines strategies, the study aims at identifying what are the preferred strategies to gain competitive advantage. Particularly, the concept of diversification (product and geographical diversification), modes of diversification (internal and external), differentiation and concentration are comprehensively discussed and applied to the liner shipping industry. Furthermore, it tries explaining what are the most significant similarities and differences in market strategies in relation to the size of each shipping line. The review of our analysis suggests that 1) all shipping lines follow a hybrid strategic model with more than one individual strategy pursued 2) larger shipping lines prefer to diversify or differentiate 2) mid-sized shipping and smaller lines tend to pursue market concentration.
Abstract: The liner shipping sector has significantly changed in recent years. Largest shipping lines have expanded their business scope becoming global carriers and a recent wave of industry consolidation has profoundly modified the market structure and, consequently, the business models followed by liners. This, coupled with weak market fundamentals, gener...
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Quality Acceptance Methods and Standards for Continuous Compaction Control Technology
Zhang Daoxiu,
Jiang Huihuang,
Gao Mingxian,
Zhang Jiandong,
Xiang Weiguo,
Yan Xiaoxia,
Guo Dong,
Zhao Chongji,
Wu Longliang
Issue:
Volume 5, Issue 4, December 2019
Pages:
82-87
Received:
12 November 2019
Published:
18 November 2019
Abstract: In order to promote the wide application of continuous compaction control technology in China, the continuous compaction control technical regulations of various countries and regions in the world are taken as research objects, and the technical characteristics and application conditions of various countries' regulations are compared and analyzed. The current continuous compaction control technology is analyzed. The main quality acceptance methods and standards, summed up the application experience of the technology around the world. The results show that the comprehensive evaluation of the comprehensive evaluation of compaction degree, compaction uniformity and compaction stability is the trend of quality control standards development. The calibration method is mainly used. The problem of water content of fine particle fillers has a significant impact on continuous compaction control and has been widely recognized. The water content of the filler needs to be controlled in engineering applications. The basic theory of continuous compaction control method is becoming more and more mature, and the development direction of the actual compaction problem is gradually developed. The accuracy requirement of continuous compaction control is gradually improved. The weak area identification method is supplemented by the incremental method of measurement. The reasonable selection of evaluation methods for engineering characteristics is an effective way to promote the successful application of continuous compaction control technology.
Abstract: In order to promote the wide application of continuous compaction control technology in China, the continuous compaction control technical regulations of various countries and regions in the world are taken as research objects, and the technical characteristics and application conditions of various countries' regulations are compared and analyzed. ...
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Metro Vehicle Axle Temperature Monitoring Device Based on Piezoelectric Vibration
Issue:
Volume 5, Issue 4, December 2019
Pages:
88-91
Received:
2 November 2019
Published:
9 December 2019
Abstract: The axle temperature monitoring of subway vehicles is a key technology to ensure the safety of trains. The existing axle temperature monitoring system is monitored by using trackside equipment or using axle temperature test paper, the system has the inferiority of poor real-time performance. In order to realize real-time and online monitoring of axle temperature, this paper presents a subway axle temperature monitoring device based on vibration energy recovery. The device is installed on the shaft end of the train axle, and uses the positive piezoelectric effect of piezoelectric ceramics to absorb vibration energy into electric energy, and continuously sends temperature signal through the radio frequency module to realize real-time monitoring of train axle temperature. A mathematical model of piezoelectric vibrator power output was established to obtain design parameters suitable for rail vehicle vibration, and the Ansys Workbench finite element analysis software was used for theoretical simulation verification. Finally, an experimental model was built and a vibration test was carried out on Shanghai metro line 1. The results show that the axial temperature monitoring device based on piezoelectric vibration can effectively obtain the axial temperature data and realize the online monitoring function.
Abstract: The axle temperature monitoring of subway vehicles is a key technology to ensure the safety of trains. The existing axle temperature monitoring system is monitored by using trackside equipment or using axle temperature test paper, the system has the inferiority of poor real-time performance. In order to realize real-time and online monitoring of ax...
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Finite Element Modeling and Static Strength Analysis on Structure Strength of the High-Speed Maglev Bogie
Xu Shimeng,
Li Cen,
Yao Yijing,
Yuan Yuqing,
Li Weiya,
Li Qiang
Issue:
Volume 5, Issue 4, December 2019
Pages:
92-96
Received:
3 November 2019
Published:
9 December 2019
Abstract: Maglev train with no mechanical contact of the innovative technology, as well as a series of excellent economic and environmental advantages came into being. More and more people pay attention to it, and it has become one of the most promising transportation means in the new century. According to the actual operation of maglev train, a boundary constraint method is proposed in this paper. On the basis of the actual operation of maglev train, a method of boundary constraint is proposed, and the finite element model is established by using HyperMesh software. Afterwards using ANSYS analysis software to analyzed the statics performance of levitation chassis under the four working conditions of maglev vehicle, and static strength of the levitation chassis based on von Mises stress was assessed. In accordance with the results, the parts with high stress are optimized. The result showed that the stress intensity on the back of the air spring mounting base is relatively high. This situation can be improved by changing the radius to 40 mm fillets. The strength of other parts meets the standard requirement and provided the basis for further optimization calculation. The results have laid a foundation for the fatigue strength test of the suspension chassis of high-speed maglev train.
Abstract: Maglev train with no mechanical contact of the innovative technology, as well as a series of excellent economic and environmental advantages came into being. More and more people pay attention to it, and it has become one of the most promising transportation means in the new century. According to the actual operation of maglev train, a boundary con...
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Influence of Moisture Content on Mechanical Properties of Autoclaved Aerated Concrete
Chunning Deng,
Weiqun Cai,
Jian Yin,
Fen Yang,
Linchen Li
Issue:
Volume 5, Issue 4, December 2019
Pages:
97-102
Received:
20 November 2019
Accepted:
16 December 2019
Published:
24 December 2019
Abstract: Autoclaved aerated concrete (AAC) is a new type of green building material rapidly developed nowadays. Moisture content plays a significant effect on its mechanical properties. In this study, a series of uniaxial compression tests were conducted to evaluate the effect of moisture content on the mechanical behaviors. During the tests, full stress-strain curves were obtained. The influence of water content on AAC stress-strain full curve shape, elastic modulus, peak stress, peak strain and ultimate strain was analyzed. The fitting equations of water content with peak stress, peak strain and elastic modulus were established. The results show that the brittleness of AAC decreased with the increased of water content, and the failure mode gradually transited from brittle to ductile failure. When the water content increased from 0% to 10%, obvious difference in the stress-strain curves can be observed. The peak stress decreased by 20.00% and 11.63% when the moisture content was 5% and 10%, respectively. However, when the water content increased from 10% to 40%, the peak stress decreased slowly. The rising section relation model of AAC stress-strain full curve can be fitted by cubic polynomial, which provided reference basis for finite element analysis.
Abstract: Autoclaved aerated concrete (AAC) is a new type of green building material rapidly developed nowadays. Moisture content plays a significant effect on its mechanical properties. In this study, a series of uniaxial compression tests were conducted to evaluate the effect of moisture content on the mechanical behaviors. During the tests, full stress-st...
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Laboratory Investigation on Mechanical Properties of Cementitious Composites with a Low Brittleness
Weiqun Cai,
Jian Yin,
Songyun Wu,
Chunning Deng,
Fen Yang,
Linchen Li,
Jiongjun Yuan
Issue:
Volume 5, Issue 4, December 2019
Pages:
103-110
Received:
28 November 2019
Accepted:
11 December 2019
Published:
24 December 2019
Abstract: In this study, laboratory tests were conducted to investigate the mechanical behaviors of cement mortars incorporated with different admixtures, such as polypropylene fiber (PP), slag, silica fume and fly ash. Orthogonal tests were designed to evaluate the effects of the admixtures on the brittleness. The flexural strengths and the compressive-flexural ratios were selected to evaluate the brittleness. The optimal proportion can be obtained when PP content was 1.6 kg/m3, and the content of fly ash, slag and silica fume was 10%, 20% and 3% of the cement content respectively. Using the optimal proportion, the 3d flexural strength of cement mortar was 5.65 MPa, which was 19% larger than the specimens without the addition of admixtures; the compressive-flexural ratio was 4.1, which was reduced by 19% in contrast to the control group. The flexural strength at 28d was 9.04 MPa, which was 13% higher than the control group; and the compressive-flexural ratio was 4.21, decreasing 24% compared to the control group. SEM technology was utilized to characterize the evolution of the microstructure induced by the addition of mineral admixtures and PP fiber. Results showed that mineral admixtures made the mortars denser, and the PP fiber formed a cross-linking structure, improving the brittle-resistance. The test results provided some guidance for the mixture design of pavement concrete with a high flexural strength and a low brittleness.
Abstract: In this study, laboratory tests were conducted to investigate the mechanical behaviors of cement mortars incorporated with different admixtures, such as polypropylene fiber (PP), slag, silica fume and fly ash. Orthogonal tests were designed to evaluate the effects of the admixtures on the brittleness. The flexural strengths and the compressive-flex...
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The Effect of High-Speed Rail on Regional Economy in China Using AHP
Issue:
Volume 5, Issue 4, December 2019
Pages:
111-117
Received:
3 November 2019
Published:
26 December 2019
Abstract: The opening of the high-speed rail is a technological revolution in the transportation industry, which reflects the comprehensive strength of the country to some extent. It generated a lot of researches on high-speed rail in transportation, tourism, economy, etc. However, there are few studies on the impact of high-speed rail on regional economic development by the analytic hierarchy process. On the basis of reading and collating related literature, the paper put forward the quantitative and qualitative methods in effect of high-speed rail (HSR) on regional economic development. According to the theory of Regional Economy development and the practical condition of high-speed rail in China, this paper provides a new evaluation index system including 2 layers (direct and indirect effects), and establishing 6 indexes for the effect of high-speed rail on regional economy in China. The weights of factors in index system are gave by using Analytic Hierarchy Process. The main conclusion from the paper is that high-speed rail a direct impact on the regional economy is greater than indirect And the following of the ranking result of the indicator regional: passenger traffic>node accessibility > regional investment benefit> tourism development> regional industrial structure> urbanization levels. This is not only a great significance to the development regional economy of China, but also applicable to other districts for the development of local economies by HSR.
Abstract: The opening of the high-speed rail is a technological revolution in the transportation industry, which reflects the comprehensive strength of the country to some extent. It generated a lot of researches on high-speed rail in transportation, tourism, economy, etc. However, there are few studies on the impact of high-speed rail on regional economic d...
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