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1 – 6 of 6Hongxu Chen, Qin Yin, Guanhua Dong, Luofeng Xie and Guofu Yin
The purpose of this paper is to establish a stiffness model of fixed joint considering self-affinity and elastoplasticity of asperities.
Abstract
Purpose
The purpose of this paper is to establish a stiffness model of fixed joint considering self-affinity and elastoplasticity of asperities.
Design/methodology/approach
The proposed model considers that asperities of different scales are interrelated rather than independent. For elastoplastic contact, a spring-damper model and an elastic deformation ratio function were proposed to calculate the contact stiffness of asperities.
Findings
A revised fractal asperity model was proposed to calculate the contact stiffness of fixed joint, the impacts of the fractal dimension, the fractal roughness parameter and the Meyer index on the contact stiffness were discussed, and the present experimental results and the Jiang’s experimental results showed that the stiffness can be well predicted by proposed model.
Originality/value
The contradiction between the Majumdar and Bhushan model and the Morag and Etsion model can be well explained by considering the interaction among asperities of different scales. For elastoplastic contact, elastic deformation ratio should be considered, and the stiffness of asperities increases first and then decreases with the increasing of interference.
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Jinliang Liu, Yanmin Jia, Guanhua Zhang and Jiawei Wang
During service period, due to the overload or other non-load factors, cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge structure…
Abstract
Purpose
During service period, due to the overload or other non-load factors, cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge structure. The purpose of this paper is to quickly realize the bearing capacity and the loss of the section stiffness through fracture characteristics and make correct judgments.
Design/methodology/approach
Through the flexural failure test of two test beams: collecting data of fracture characteristics and section stiffness loss value. According to the fracture characteristic data, the flexural stiffness of the section is obtained by the nonlinear calculation method, and the results are verified by test data. Data regression method is used to establish the section flexural stiffness loss ratio calculation formula, nominal tensile strain at the bottom edge of the cross-section used as a variable factor, and the accuracy of this formula is verified by comparing the flexural failure test results of pre-stressed hollow plates.
Findings
The loss of the flexural stiffness of section shows the decrease trend of first-fast-then-slow and the structural stiffness is sensitive to the initial cracking of beam. The calculation formula on the loss ratio of the flexural stiffness of section established with the nominal tensile stress at the bottom edge of beam as a variable is accurate and feasible, it realizes the possibility of assessing the stiffness loss of pre-stressed concrete structure by adopting the statistic parameters on crack characteristics.
Originality/value
A method for quickly determine the stiffness loss of structures by using fracture characteristics is established, and using this method, engineers can quickly determine whether a bridge is a dangerous bridge, without loading test. So, this method not only ensures the safety of human life, but also saves money.
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Jinliang Liu, Yanmin Jia, Guanhua Zhang and Jiawei Wang
During service period, due to the overload or other non-load factors, diagonal cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge…
Abstract
Purpose
During service period, due to the overload or other non-load factors, diagonal cracks of the pre-stressed concrete beam are seriously affecting the safety of the bridge structure. The purpose of this paper is to quickly realize the shear bearing capacity and shear stiffness through maximum width of the diagonal cracks and make correct judgments.
Design/methodology/approach
Through the shear failure test of four test beams, collecting data of diagonal cracks and shear stiffness loss value. According to the deformation curve of the shear stiffness, and combined with the calculation formula of the maximum width of diagonal cracks, the formula for calculating the effective shear stiffness based on the maximum width of diagonal cracks is deduced, then the results are verified by test data. Data regression method is used to establish the effective shear stiffness loss ratio calculation formula, the maximum width of diagonal cracks used as a variable factor, and the accuracy of this formula is verified by comparing the shear failure test results of pre-stressed hollow plates.
Findings
With the increase in width of the diagonal crack, the loss rate of shear stiffness of the concrete beams is initially fast and then becomes slow. The calculation formulae for shear stiffness based on the maximum width of the diagonal cracks were deduced, and the feasibility and accuracy of the formulae were verified by analysis and calculation of shear test data.
Originality/value
A method for quickly determine the shear stiffness loss of structures by using maximum width of the diagonal cracks is established, and using this method, engineers can quickly determine effective shear stiffness loss ratio, without complex calculations. So this method not only ensures the safety of human life, but also saves money.
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– This paper aims to review the literature on mobile information services. It considers only peer-reviewed papers published in English between 2004 and 2014.
Abstract
Purpose
This paper aims to review the literature on mobile information services. It considers only peer-reviewed papers published in English between 2004 and 2014.
Design/methodology/approach
The method of systematic review was adopted to collect and analyse the relevant literature. The searches were conducted during the last week of July 2014 on different databases, and in total, 76 papers were considered after applying inclusion and exclusion criteria.
Findings
Seven themes emerged: “introducing mobile libraries”, “reporting on current trends”, “exploring users’ perceptions of libraries’ mobile services”, “presenting libraries’ mobile services”, “presenting mobile technology use in libraries”, “reporting case studies” and “reporting on evaluation of libraries’ mobile services”. It is evident that research on mobile libraries is very recent and focuses mainly on raising the Library and Information Science profession’s awareness of providing mobile information services.
Research limitations
This literature review focused only on peer-reviewed papers published between 2004 and 2014 in English.
Originality/value
This paper summarises and critically presents the relevant literature on libraries offering mobile information services. It informs libraries and librarians’ understanding of recent developments in mobile technology for the successful provision of information services.
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Ye Yuan, Gang Liu, Rui Dang, Stephen Siu Yu Lau and Guanhua Qu
The purpose of this paper is to identify the design elements of environmental features that affect consumer experience in shopping malls and develop a comprehensive…
Abstract
Purpose
The purpose of this paper is to identify the design elements of environmental features that affect consumer experience in shopping malls and develop a comprehensive understanding of the relationship between architectural design and consumer experience.
Design/methodology/approach
Through the systematic literature review, 13 design elements were obtained and then verified through interviews of 30 professional designers. The obtained elements were made into a questionnaire to collect data across China from 1,016 consumers of different groups. Data were analyzed using cluster analysis, principal component analysis and difference analysis.
Findings
The results show that design elements that influence consumer experience in shopping malls are a four-dimensional construct: visual atmosphere, physical environment comfort, space structure and business planning, among which space structure and business planning play a larger role in the consumer experience. In addition, the perception differences of consumers for those elements are significant due to the individual differences.
Originality/value
This paper comprehensively investigates the architectural design elements affecting consumer experience in the Chinese mall context. Moreover, it provides unique insights about the relationship between architectural design and consumer experience by exploring the categories, weights and perception differences of those elements.
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Jing Wang, Yinghan Wang, Yichuan Peng and Jian John Lu
The operation safety of the high-speed railway has been widely concerned. Due to the joint influence of the environment, equipment, personnel and other factors, accidents…
Abstract
Purpose
The operation safety of the high-speed railway has been widely concerned. Due to the joint influence of the environment, equipment, personnel and other factors, accidents are inevitable in the operation process. However, few studies focused on identifying contributing factors affecting the severity of high-speed railway accidents because of the difficulty in obtaining field data. This study aims to investigate the impact factors affecting the severity of the general high-speed railway.
Design/methodology/approach
A total of 14 potential factors were examined from 475 data. The severity level is categorized into four levels by delay time and the number of subsequent trains that are affected by the accident. The partial proportional odds model was constructed to relax the constraint of the parallel line assumption.
Findings
The results show that 10 factors are found to significantly affect accident severity. Moreover, the factors including automation train protection (ATP) system fault, platform screen door and train door fault, traction converter fault and railway clearance intrusion by objects have an effect on reducing the severity level. On the contrary, the accidents caused by objects hanging on the catenary, pantograph fault, passenger misconducting or sudden illness, personnel intrusion of railway clearance, driving on heavy rain or snow and train collision against objects tend to be more severe.
Originality/value
The research results are very useful for mitigating the consequences of high-speed rail accidents.
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