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1 – 10 of 10Changsheng Wang, Yang Wang, Caixia Yang, Xiangkui Zhang and Ping Hu
Severe accuracy loss may occur when finite element comes to the distorted mesh model, and the calculation may fail when element mesh degenerates into concave quadrangle or the…
Abstract
Purpose
Severe accuracy loss may occur when finite element comes to the distorted mesh model, and the calculation may fail when element mesh degenerates into concave quadrangle or the element boundary is curved. This is a valuable research topic, and many efforts have been made to develop new finite element models. This paper aims to propose two quasi-conforming membrane elements based on the assumed stress quasi-conforming method and fundamental analytical solutions to overcome the difficulties.
Design/methodology/approach
First, the fundamental analytical solutions which satisfied both the equilibrium and the compatibility relations of plane stress problem are used as the initial assumed stress of both elements. Then, the stress-function matrices are used as the weighted functions to weaken the strain-displacement equations, which makes only string-net functions on the boundary of the elements are needed in the process of strain integration. Finally, boundary interpolation functions expressed by unknown nodal displacement parameters are adopted to the process of strain integration.
Findings
The formulations of both elements are simple and concise, and the elements are immune to the distorted mesh, which can be used to the mesh shape degenerates into a triangle or concave quadrangle and curved-side element. The results of the numerical tests have proven that the new models possess high accuracy.
Originality/value
New formulations of quasi-conforming method are described is detail, and the new strategy exhibits advantages of both analytical and discrete methods.
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Keywords
Changsheng Wang, Xiao Han, Caixia Yang, Xiangkui Zhang and Wenbin Hou
Numerous finite elements are proposed based on analytical solutions. However, it is difficult to find the solutions for complicated governing equations. This paper aims to present…
Abstract
Purpose
Numerous finite elements are proposed based on analytical solutions. However, it is difficult to find the solutions for complicated governing equations. This paper aims to present a novel formulation in the framework of assumed stress quasi-conforming method for the static and free vibration analysis of anisotropic and symmetric laminated plates.
Design/methodology/approach
Firstly, an initial stress approximation ruled by 17 parameters, which satisfies the equilibrium equations is derived to improve the performance of the constructed element. Then the stress matrix is treated as the weighted function to weaken the strain-displacement equations. Finally, the Timoshenko’s laminated composite beam functions are adopted as boundary string-net functions for strain integration.
Findings
Several numerical examples are presented to show the performance of the new element, and the results obtained are compared with other available ones. Numerical results have proved that the new element is free from shear locking and possesses high accuracy for the analysis of anisotropic and symmetric laminated plates.
Originality/value
This paper proposes a new QC element for the static and free vibration analysis of anisotropic and symmetric laminated plates. In contrast with the complicated analytical solutions of the equilibrium equations, an initial stress approximation ruled by 17 parameters is adopted here. The Timoshenkos laminated composite beam functions are introduced as boundary string-net functions for strain integration. Numerical results demonstrate the new element is free from shear locking and possesses high accuracy for the analysis of anisotropic and symmetric laminated plates.
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Caixia Chen, Tongyu Gu, Yuru Cai and Yixiong Yang
The purpose of this paper is to develop a novel research model to examine the relationship among information sharing (IS), supply chain integration (SCI), operational performance…
Abstract
Purpose
The purpose of this paper is to develop a novel research model to examine the relationship among information sharing (IS), supply chain integration (SCI), operational performance (OP) and business performance (BP) in the fashion supply chains.
Design/methodology/approach
A survey of 247 executives from Chinese fashion brand firms was conducted and the data were analyzed to investigate how IS affects the organizational BP. Structural equation modeling (SEM) was applied to study the relationship among IS, SCI, OP and BP.
Findings
The empirical research results indicate that IS is critical to enhance the SCI and OP, and both SCI and OP exert mediating effects on BP of fashion brands. This result also reveals constructive suggestions that allow fashion brands to strengthen their SCI and OP, as well as BP.
Research limitations/implications
Multiple data sources were applied to develop the sampling frame, and respondents were selected (according to their experience and position) to ensure they had the knowledge and expertise to provide valid response. However, this could not guarantee the adequacy of the sample. This limitation is compounded by the reliance on a simple respondent per firm, which precludes testing for inter-rater reliability.
Practical implications
The empirical findings provide an enhanced understanding of the relationship among IS, SCI, OP and BP in Chinese fashion brand settings. The research results will help fashion brands to improve supply chain efficiency and enhance company performance.
Originality/value
Although previous studies have realized that the value of IS varies in different industries, few have specifically explored the impact on the fashion industry characterized by short life cycles, high volatility, low predictability and high impulse purchasing. To fill this knowledge gap, the present study employed a questionnaire survey and SEM techniques to explore the relationship among IS, SCI, OP and BP in the fashion supply chain. Comprehending the impact mechanism of IS on organizational performance can provide useful management insights into the development of effective strategies that allow enterprise to improve BP.
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Ying Huang, Chao Hao, Jian Liu, Xiaohui Guo, Yangyang Zhang, Ping Liu, Caixia Liu, Yugang Zhang and Xiaoming Yang
The purpose of this study is to present a highly stretchable and flexible strain sensor with simple and low cost of fabrication process and excellent dynamic characteristics…
Abstract
Purpose
The purpose of this study is to present a highly stretchable and flexible strain sensor with simple and low cost of fabrication process and excellent dynamic characteristics, which make it suitable for human motion monitoring under large strain and high frequency.
Design/methodology/approach
The strain sensor was fabricated using the rubber/latex polymer as elastic carrier and single-walled carbon nanotubes (SWCNTs)/carbon black (CB) as a synergistic conductive network. The rubber/latex polymer was pre-treated in naphtha and then soaked in SWCNTs/CB/silicon rubber composite solution. The strain sensing and other performance of the sensor were measured and human motion tracking applications were tried.
Findings
These strain sensors based on aforementioned materials display high stretchability (500 per cent), excellent flexibility, fast response (approximately 45 ms), low creep (3.1 per cent at 100 per cent strain), temperature and humidity independence, superior stability and reproducibility during approximately 5,000 stretch/release cycles. Furthermore, the authors used these composites as human motion sensors, effectively monitoring joint motion, indicating that the stretchable strain sensor based on the rubber/latex polymer and the synergetic effects of mixed SWCNTs and CB could have promising applications in flexible and wearable devices for human motion tracking.
Originality/value
This paper presents a low-cost and a new type of strain sensor with excellent performance that can open up new fields of applications in flexible, stretchable and wearable electronics, especially in human motion tracking applications where very large strain should be accommodated by the strain sensor.
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Shu Yi, Lin Xiao, Yong Zhang, Dujuan Duan and Maksim G. Blokhin
This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench…
Abstract
This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench samples were taken from Huangling Mine 2. The average content of barium (3701 mg/kg) was about 23 times higher than that of common world coals. Terrestrial higher plants were the main coal-forming parent material. Relying on the parameters of OEP, Pr/Ph and so on, there is little correlation between organic geochemical characteristics and barium enrichment. Therefore, organic material has little influence on the process of coal-forming and the enrichment of barium.
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Chinese consumers’ cross-border internet shopping, so called “haitao” is an emerging popular trend in China. Haitao can be understood as service innovation process because it…
Abstract
Purpose
Chinese consumers’ cross-border internet shopping, so called “haitao” is an emerging popular trend in China. Haitao can be understood as service innovation process because it creates new market spaces and provides differentiated values for Chinese customers.
Design/methodology/approach
This study aims to explore the service innovation strategies and success factors of haitao business in the Chinese market. The authors selected two successful haitao sites of Amazon.cn and Gmarket.co.kr, as representatives of a global player and a niche player, and conducted a comparative case study to analyze their service innovation strategies and key success factors.
Findings
This comparative case analysis based on value chain framework revealed some common success factors such as trust, advanced system and alliances as well as their service innovation efforts. Amazon has advantages such as efficient logistics system and global sourcing, whereas Gmarket has advantages such as product category, sales promotions, and payment system.
Originality/value
This study provides some implications for managers with localization, alliances and platform strategies.
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Caixia Chao, Xin Mei, Yongle Wei and Lijin Fang
This paper aims to design a walking-clamp mechanism for the inspection robot of transmission line. The focus for this design is on climbing ability and obstacle-crossing ability…
Abstract
Purpose
This paper aims to design a walking-clamp mechanism for the inspection robot of transmission line. The focus for this design is on climbing ability and obstacle-crossing ability with a goal to create a novel walking-clamp mechanism that can clamp not only the line but also the obstacle.
Design/methodology/approach
A novel clamping jaw used in the walking-clamp mechanism is proposed. The clamping wheel is mounted on the lower end of clamping jaw to reduce the friction between the clamping jaw and the line, and the top end of clamping jaw is designed as a hook structure to clamp the obstacle. The working principle and force states of the walking-clamp mechanism clamping the line and obstacle are analyzed, and the simulation and prototype experiments are carried out.
Findings
The experimental results show that this mechanism can clamp the obstacle steadily, and the clamping forces of the front and back pairs of clamping jaws are almost equal during robot walking along the catenary-shaped line. It is in agreement with the theoretical analysis, and it demonstrates that this mechanism can meet the working requirements of inspection robot.
Practical implications
This novel mechanism can be used for inspection robot of transmission line, and it is beneficial for robot to complete long-distance inspection works.
Social implications
It stands to reduce costs related to inspection and improve the inspection efficiency.
Originality/value
Innovative features include its structure, working principle and force states.
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Keywords
Yin Kedong, Zhe Liu, Caixia Zhang, Shan Huang, Junchao Li, Lingyun Lv, Xiaqing Su and Runchuan Zhang
In recent years, China's marine industry has maintained rapid growth in general, and marine-related economic activities have continued to improve. The purpose of this research is…
Abstract
Purpose
In recent years, China's marine industry has maintained rapid growth in general, and marine-related economic activities have continued to improve. The purpose of this research is to analyze the basic situation of China's marine economy development, identify the problems therein, forecast development trends and propose policy recommendations accordingly.
Design/methodology/approach
This research conducts a comprehensive and detailed analysis of the development of China's marine economy with rich data in diversified aspects. The current situation of China's marine economy development is analyzed from the perspective of scale and structure, and the external and internal development environment of China's marine economy is discussed. With the application of measurement and prediction method such as trend extrapolation, exponential smoothing, grey forecasting and neural network method, the future situation of China's marine economy development is forecasted.
Findings
In a complex environment where uncertainties at home and abroad have increased significantly, China's marine economy development suffers tremendous downward pressure in recent years. As China has achieved major achievements in the prevention and control of the COVID-19 epidemic, the marine economy development will gradually return to normal. It is estimated that the gross marine production value in 2022 will exceed 10 trillion yuan. China's marine economy will continue to maintain a steady growth trend in the future, and its development prospects will remain promising.
Originality/value
This research explores the current situation and trends of China's marine economy development and puts forward policy recommendations to promote the steady and health development of China's marine economy accordingly.
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Haifeng Fang, Yangyang Wei and Shuo Dong
Tactile sensation is an important sensory function for robots in contact with the external environment. To better acquire tactile information about objects, this paper aims to…
Abstract
Purpose
Tactile sensation is an important sensory function for robots in contact with the external environment. To better acquire tactile information about objects, this paper aims to propose a three-layer structure of the interdigital flexible tactile sensor.
Design/methodology/approach
The sensor consists of a bottom electrode layer, a middle pressure-sensitive layer and a top indenter layer. First, the pressure sensitive material, structure design, fabrication process and circuit design of the sensor are introduced. Then, the calibration and performance test of the designed sensor is carried out. Four functions are used to fit and calibrate the relationship between the output voltage of the sensor and the contact force. Finally, the contact force sensing test of different weight objects and the flexible test of the sensor are carried out.
Findings
The performance test results show that the sensitivity of the sensor is 0.93 V/N when it is loaded with 0–3 N and 0.23 V/N when it is loaded with 3–5 N. It shows good repeatability, and the cross-interference between the sensing units is generally low. The contact force sensing test results of different weight objects show that the proposed sensor performs well in contact force. Each part of the sensor is a flexible material, allowing the sensor to achieve bending deformation, so that the sensor can better perceive the contact signs of the grasped object.
Practical implications
The sensor can paste the surface of the paper robot’s gripper to measure the contact force of the grasping object and estimate the contour of the object.
Originality/value
In this paper, a three-layer interdigital flexible tactile sensor is proposed, and the structural parameters of the interdigital electrode are designed to improve the sensitivity and response speed of the sensor. The indenter with three shapes of the prism, square cylinder and hemisphere is preliminarily designed and the prism indenter with better conduction force is selected through finite element analysis, which can concentrate the external force in the sensing area to improve the sensitivity. The sensor designed in this paper can realize the measurement of contact force, which provides a certain reference for the field of robot tactile.
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Yung Sin Chong, Keat Hoe Yeoh, Pei Ling Leow and Pei Song Chee
This paper aims to report a stretchable piezoresistive strain sensor array that can detect various static and dynamic stimuli, including bending, normal force, shear stress and…
Abstract
Purpose
This paper aims to report a stretchable piezoresistive strain sensor array that can detect various static and dynamic stimuli, including bending, normal force, shear stress and certain range of temperature variation, through sandwiching an array of conductive blocks, made of multiwalled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) composite. The strain sensor array induces localized resistance changes at different external mechanical forces, which can be potentially implemented as electronic skin.
Design/methodology/approach
The working principle is the piezoresistivity of the strain sensor array is based on the tunnelling resistance connection between the fillers and reformation of the percolating path when the PDMS and MWCNT composite deforms. When an external compression stimulus is exerted, the MWCNT inter-filler distance at the conductive block array reduces, resulting in the reduction of the resistance. The resistance between the conductive blocks in the array, on the other hand, increases when the strain sensor is exposed to an external stretching force. The methodology was as follows: Numerical simulation has been performed to study the pressure distribution across the sensor. This method applies two thin layers of conductive elastomer composite across a 2 × 3 conductive block array, where the former is to detect the stretchable force, whereas the latter is to detect the compression force. The fabrication of the strain sensor consists of two main stages: fabricating the conducting block array (detect compression force) and depositing two thin conductive layers (detect stretchable force).
Findings
Characterizations have been performed at the sensor pressure response: static and dynamic configuration, strain sensing and temperature sensing. Both pressure and strain sensing are studied in terms of the temporal response. The temporal response shows rapid resistance changes and returns to its original value after the external load is removed. The electrical conductivity of the prototype correlates to the temperature by showing negative temperature coefficient material behaviour with the sensitivity of −0.105 MΩ/°C.
Research limitations/implications
The conductive sensor array can potentially be implemented as electronic skin due to its reaction with mechanical stimuli: compression and stretchable pressure force, strain sensing and temperature sensing.
Originality/value
This prototype enables various static and dynamic stimulus detections, including bending, normal force, shear stress and certain range of temperature variation, through sandwiching an array of conductive blocks, made of MWCNT and PDMS composite. Conventional design might need to integrate different microfeatures to perform the similar task, especially for dynamic force sensing.
Details