bluuebunny/crossref_metadata_2025 huggingface dataset:
Vehicle-track dynamic interaction analysis of a metro vehicle
Authors: Han Junchen , Jiang Yongzhi
Published: April 2020

In this paper, comparison of results between the self-programming model (considering the track flexibility) and SIMPACK model (considering only fastener support) is carried out. The wheelset vibration is more obviously for the self-programming model as the track flexibility is considered. For the traditional dynamic calculation, the SIMPACK multi-rigid-body model is acceptable. Two kinds of harmonic vibrations in the car body for a metro car, which were found in the service operations, are reproduced by using self-programming model. High tread conicity leds to the harmonic vibrations in the car body about 4.8Hz. Reducing wheel conicity can improve the bogie hunting stability, and solve this problem. Another harmonic vibration with the frequency of about 2.2Hz in the car body is caused by the constant excitation wavelength in the track, which causes vibration transmited through the primary and secondary suspensions to the carbody. To reduce this harmonic vibration, more advanced suspensions are needed.
Impact of land use and land cover change on water quality: a study of Fuxian Lake
Authors: Zhang Xiaolun , Shao Yanyan
Published: April 2020

Water quality and basin ecological environment are seriously threatened by development around the lake. The thesis intends to assess basin land use and land cover changes impact on water quality in Fuxian Lake. To achieve this purpose, six periods Landsat images from 1990 to 2016 were used. By using remote sensing and GIS software, the five images were classified into six land use classes. The water quality information was obtained by investigation and collection. Correlation coefficient between LUCC and water quality was celebrated based on SPSS software. The results revealed that, the study area underwent an increase in construction land and farm land with the region development; but forest land and grassland are gradually reduced. In addition, potassium permanganate index is gradually increased. Furthermore, total nitrogen is significantly positively correlated with farmland and construction land, negatively correlated with forest land and grass land. In the final part of the thesis, it is believed that a series land use and land cover changes has happened due to development of Lake Basin, which poses a serious threat to water quality.
Analysis of Impacts of Crossing Bridges on Flood Control and Dike Safety
Authors: Hui Teng , Lirong Wang , Bin Yan , Bing Geng
Published: April 2020

The construction of bridges across rivers mostly involves occupying river sections and dike sections, which will adversely affect flood control of rivers and the safety and stability of dikes. Taking an actual project for example, this paper puts forward some ideas and methods for the analysis of impacts of crossing bridges on flood control and dike safety, analyses and evaluates effects of raising of water level, dike foot erosion, seepage stability and anti-sliding stability. Finally, suggestions and measures for bridge construction and dike protection are raised.
Comparison and correction of element measurements using XRF core scanning and ICP-AES methods in lacustrine sediments
Authors: Cheng Aiying , Yu Junqing , Gao Chunliang , Zhang Lisha
Published: April 2020

An integrated analysis has been carried out on core dated by qualitative X-ray fluorescence core scanning combination of quantitative ICP-AES in order to characterize the extent of elements Cd, Cr, Cu, Zn, and Pb in the Lake Toson in the northeastern Tibet Plateau. When combining both the quantitative and qualitative measurements, we observed a significantly positive correlation. Comparing the ratios between element intensities and concentration, we found that the XRF element intensities were related to the amount of water. Using the intensity of Cl as an indicator of water content, the element intensities of Cd, Cr, Cu, Zn, and Pb in the core samples were corrected. The correlation coefficients of each pairs of the two datasets among Cd, Cr, Cu, Zn, and Pb were significantly raised. These data sets with highly correlations were used to produce a transfer function to relate XRF element intensity with element concentration. Calculated element concentrations from the intensities show only minor differences from concentrations obtained by ICP-AES, indicating XRF core scanners are a very useful tool for measuring element concentration in lacustrine sediments.
Evaluation of bidding risk for wind farm construction projects
Authors: Shanshan Liu
Published: April 2020

With the rapid development and expansion of wind power generation capacity in China, the risk of wind farm construction projects has been paid more and more attention. Based on the method of can-expandable element and multi-level fuzzy comprehensive evaluation method, this paper makes an empirical analysis of the bidding risk of the wind farm construction project of Xintiandi Energy Company in Hebei Province. The research shows that the can-expander element method is more accurate in risk evaluation because there are no different evaluation principles, which can provide effective support for decision makers.
The Security Risk Evaluation of Railway Construction Based on CIM Model
Authors: Mei Tingyu , Luo Yiqing , Chen Fenfen , Wu Lang
Published: April 2020

In this paper, the CIM model is used to evaluate and manage the safety risk of subway construction. Taking Nanchang Metro Line 4 bid section 3 as an example, the total safety risk of the project construction is estimated, and the corresponding countermeasures are proposed, which is of certain significance to avoid and respond to the construction project risk. The results show that the possibility of moderate total safety risk in the construction of the third bid section of Nanchang Metro Line 4 is relatively large, and the probability is about 40%.
Change thinking and focus on the long term—from the new campus location of Wuhan Polytechnic University
Authors: Zhao Huiyan
Published: April 2020

The location of the new campus of Wuhan Polytechnic University reflects how universities view the development. The common way is to expand the land use and scale. Local colleges and universities need to change thinking and realize that development is not simply to build campuses to make them bigger, but to make full use of the conditions to make them stronger. Development should focus on the long term and improve the competitiveness of personnel training. If it is necessary to develop a new campus, it is suggested not to be located far away from the old campus, or be located in a place with convenient transportation, and if it is necessary to be located in another city, it is better to be in a city with better conditions.
Fluctuation Effect of Supply and Demand in the Assembled Property Market: An Empirical Analysis of China from 2001 to 2018
Authors: Luo Gangqiang , Wang Qin
Published: April 2020

This paper established the disequilibrium degree model of effective supply and effective demand in the assembled property market. Based on the statistical data from 2001 to 2018, the paper estimated and tested the parameters of the disequilibrium model of effective supply and demand, and calculated the disequilibrium degree of effective supply and demand in China’s assembled property market. The results indicated that China’s assembled property market was not effective and equilibrium, but obviously imbalanced and fluctuated. The research results provided strong empirical evidence for revealing that price distortion was one of the important factors causing the disequilibrium in China’s assembled property market. In order to develop healthily and improve the level of social welfare, the government should take it as a basic policy in the future to eliminate the disequilibrium of effective supply and demand in the assembled property market.
ABC Analysis: A Qualitative Case Study on Inventory Management in Giant Superstore Taman Connaught, An Outlet Of GCH Retail (Malaysia) SDN. BHD.
Authors: Jayakumaran Shamani , Shan Wong Zi , Daud Dazmin
Published: April 2020

This study aimed to understand the inventory management of Giant Superstore Taman Connaught. The study was qualitative study that explored the ABC analysis efficiency of inventory management in Giant Superstore, Taman Connaught an outlet of GCH Retail (Malaysia) SDN. BHD. ABC analysis was one method to manage the inventory management who good position was arranged according to the category such as A category product was high in value but low in quantity and C category product was low in value and high in quantity. The elements that were selected as significance included the product consumption rate, carrying cost and replenishment product lead time which contributed toward ABC analysis of inventory management efficiency in Giant Superstore. The study indicated dissimilarities in controlling the inventory in Giant superstore. The study found Giant had used POM.net in their inventory management since this software from ABC tool. HR manager needs to recruit quality skilled workers that have proper qualifications and acceptable for particular job duties.
A review of airport runway capacity evaluation model
Authors: Lei Jichao , Chong Xiaolei , Chen Dongfang , Chen Zhenglei , Chen Qiqi
Published: April 2020

In this paper, we analyze the domestic scholars about the airport runway capacity evaluation model, and they are mainly the analysis and introduction of some commonly used runway capacity evaluation methods and specific runway capacity evaluation models. These models respectively include the takeoff and landing capacity of aircraft, and give the calculation methods of runway capacity in various cases. By seeking the similarities and differences of these evaluation models, the future research focus and direction are put forward.
Risk estimation of large complex bridge construction based on factor analysis
Authors: Li Qingfu , Lei Jia , Tian Wenjie , Yan Yaqian , Zhang Haiyang , Zhang Haiwei , Xiang Qunhua
Published: April 2020

This paper investigates and analyzes the risk factors of large-scale complex bridge construction through questionnaire survey and Delphi method, and obtains the risk factors and basic data that affect the construction of large complex bridges. On this basis, according to the principle of factor analysis, using SPSS V21.0 software to statistically analyze the basic data, the main factors affecting the construction risk of large complex bridges and their importance index are obtained, which provide a basis for the development of control decisions. The application of the example shows that the method given in this paper is simple in operation and the result is clear. According to the size of the factor importance index, measures can be taken to deal with major risks to ensure the smooth construction of the bridge.
A causality analysis between spatial differences in economic development and transporation development in China
Authors: Jiang Shangnan , Jiang Xiushan
Published: April 2020

This paper analyzes the spatial differences in transportation development and regional economic development in the whole and eight economic regions of China from 1997 to 2017, as well as their Granger causality. The basic conclusions include that the spatial differences in national highway and railway development is more significant than that in economic development. The transportation development of each province in the Northwest Economic Zone is very different. The imbalance of economic development in the middle reaches of the Yangtze River and Southwest Economic Zone is increasing. There is a bidirectional causal relationship between the spatial differences of the highway development and economic development for the country. Also, a one-way causal relationship from the unbalanced development of economy to the unbalanced development of railway is tested in Northwest Economic Zone, and in the Eastern and Southern coastal economic zones, the unbalanced development of highways Granger cause the unbalanced development of economy.
Application of 5G in modern supply chain scenario
Authors: Li Runqi , Wang Zun , Wang Zhisen
Published: April 2020

The supply chain is an organization form of product design, procurement, production, sales, service and so on. Continuous innovation and development of information technology and information infrastructure have promoted the continuous evolution of supply forms. With the emergence of 5G, a mobile integrated communication system that includes communication access, interconnection and things, it has developed into a modern supply chain featuring social organization coordination. This paper discusses the existence of binary space and the properties of unified digital information space, and the evolution process from the main supply chain to the platform supply chain and then to the modern supply chain. It also expounds the relationship between modern supply chain and social development, discusses the application of 5G collaborative technology in modern supply chain.
Foundation settlement prediction of immersed tunnel based on monitoring data
Authors: Li Bin , Chen zhijun , Liu Zhao
Published: April 2020

Based on the actual project, through the simulation of the construction steps and the inversion analysis of the monitoring data, the settlement of immersed tube tunnel is predicted. Through analysis, it is found that the whole foundation soil layer of immersed tube tunnel appears rebound, the maximum rebound is 0.045m, and the maximum rebound appears on the surface of the foundation trough. As the depth of the soil deepens, the rebound decreases gradually. After the construction is completed, the vertical strain curves of the immersed tube model are all distributed in a saddle shape. After the immersed tube strain is stable, the strain variables of the immersed tube increase with time basically unchanged. 1000 days after the completion of backfilling, the maximum post-construction settlement is 0.0035m.
Safety Risk Analysis of Bridge Rhombic Hanging Basket Construction Based on WBS-RBS and Rough Set Theory
Authors: Li Qingfu , Qian Huajie , Pei JunJie , Wang Saisai , Lei Jia
Published: April 2020

Because of its simple structure, light static load and no balance-weight, the rhombic hanging basket has become one of the most widely used forms in bridge hanging basket construction. In the construction process of rhombic hanging basket, there are often high risks and hidden dangers, which may cause serious engineering accidents and losses. If we can analyze these risks in the early stage of the construction of hanging basket, we can not only provide security for the construction process, but also provide basis for the construction safety management. In this paper, a comprehensive evaluation model is established by using Work Breakdown Structure- Risk Breakdown Structure and rough set theory. This model uses WBS- RBS coupling to form the association between the construction risk and the operation activities of the hanging basket, and the risk decomposition matrix is constructed to identify the risk of the whole hanging basket construction process in detail, and each risk factor is corresponding to each bottom work package. Then, rough set theory is used to determine the weight of risk in each underlying work package. Finally, the risk degree of each operation unit in the construction process is sorted according to the weight value of the risk contained, and then the high-risk links in the construction process of hanging basket can be clearly understood, so as to provide basis for construction risk management.
Analysis of Land Use Change in Jining City
Authors: Lu Nanjia , Xiao Xingyuan
Published: April 2020

Based on the LANDSAT remote sensing image data of 2000, 2005, 2010 and 2015, this paper applies RS, GIS, mathematical statistics and other methods, mainly about land use transfer matrix, single land use dynamic and comprehensive land use dynamic to analyse land use change in Jining City during the period from 2000 to 2015. The results show that: (1) The transfer intensity of grass is gradually increasing. Dry land and house-site in the countryside are transferred largely into town house. The transfer between dry land and house-site in the countryside is obvious. The imported area of waters is always larger than the exported area in three periods. Retention rate of dry land has remained relatively high. In addition, the unutilized land retention rate varies greatly. (2) The single dynamic of paddy field, town house and unutilized land are large, indicating changes of these types are intensive; the lower dynamic of dry land and waters indicates the stability of these types is good. The comprehensive land use dynamics first decreased and then increased, indicating that the intensity of land use change in Jining City first decreased and then increased, and the overall land use change is large.
Research on residential differentiation in urban fringe areas from the perspective of spatial justice – A Case Study of Xi’an City
Authors: Yang Xiaojun , Li Xiuyuan , Kong Ziqi , Lei Lei
Published: April 2020

Residence is one of the four functions of the city. The spatial layout of the residential area affects the sustainable development of the city. With the rapid development of social economy and the continuous expansion of urban space, the living space structure in the marginal area of Xi’an has been adjusted, and the living space differentiation has become increasingly obvious. Based on the theory of space justice and using the methods of space analysis, statistical analysis and field research, this paper concludes that the core of living space in the edge area of Xi’an lies in the city center, and the future development direction is northeast and southwest. The characteristics of housing price are that the middle price of residential area is the most and the number of high-end and low-end residential area is relatively small. The housing types are divided into four categories: high, high-medium, medium and low. The marginalization of residential areas is high, the middle and high-end residential areas are multi-centralized, and the middle and low-priced residential areas are marginalized, and the degree of regional differentiation is gradually deepening. This is an important feature of the differentiation of residential areas in the marginal areas. Finally, the fairness of the living space structure in the social area was evaluated, and corresponding optimization suggestions were put forward.
Research on the Spatial Integration of Traditional Villages under the Concept of “Live Heritage”—Taking Chang’an district of Xi’an as an example
Authors: Yang Xiaojun , Shi Tingli , Li Xiuyuan , Kong Ziqi
Published: April 2020

The protection and sustainable development of traditional villages is an important issue of common concern in all walks of life. Taking the Yaotou Village of Weinan City in Shanxi Province as an example, this paper simulates the spatial and temporal evolution process of the Sansheng space in Yaotou Village through questionnaire interview and GIS spatial analysis method. For the revitalization of the handicraft village provides a reference.
Study on the Rural Revitalization Path in the Continuum Depressed Area from the Perspective of Inclusive Green Development: A case study of Qinba Mountain Area
Authors: Yang Xiaojun , Liu Qin , Cao Qun , Lei Lei
Published: April 2020

Implementing the rural revitalization strategy is the action plan for rural construction and development in the new era, and it is the general requirement and general grasp of the work of “agriculture, rural areas and farmers “. Based on the four-dimensional relationship between resource development, poverty alleviation, community participation and ecological protection, this paper analyzes the poverty situation, causes and development characteristics of Ankang in Qinba mountain area. The study found that Ankang City in Qinba Mountain Area has many poor people and a deep poverty. It faced the dual pressures of protecting the ecological environment and fighting poverty. From the niche point of view, Ankang City is located in ecologically fragile areas and ecological diversity protection areas, and from the perspective of economic development, it is a contiguous destitute area with deep poverty. Therefore, rural revitalization in the region must weigh these relationships and issues. From the perspective of inclusive green development, it proposes a rural revitalization path suitable for the region, adheres to precise poverty alleviation, promotes equalization of opportunities for the poor to participate in rural development, increases the rights of the poor in the system, and protects the ecological environment. To provides a theoretical reference for scientific formulation of rural revitalization strategic planning and early realization of rural revitalization.
Inverse geochemical modelling of pit lake waters in the Zeida abandoned mine (Morocco)
Authors: El Alaoui L , Dekayir A , Rouai M
Published: April 2020

In the high Moulouya watershed, the exploitation of the Zeida mine between 1972 and 1985 generated huge masses (millions of tons) of mining waste (Pb, Zn). This activity created large pits currently filled with stagnant water which are in permanent contact with remaining ore deposit.

The interaction of rainwater with rocks and minerals lead to the enrichment of Water Lake with heavy metals.

An inverse geochemical modelling carried out on water sampled in ZA and ZL1 lakes made it possible to highlight the chemical reactions occurring between rainwater and ore deposit and which would control the chemistry of these waters.
Thermophysical characterization of a new clay-based construction material from the Atlas region
Authors: Lkouen A. , Meskini A. , Lamrani M. , Khabbazi A.
Published: April 2020

As part of the valorization of local materials and the search for energy efficiency in the building sector, a thermophysical study was carried out on a new clay-based composite material from the Atlas region reinforced by peanut shells, which constitute an abundant ecological and untapped waste. In this study, a series of samples (100×100×26 mm3) of this composite are elaborated at different mass fractions of peanut shells. The thermal parameters are estimated by metrological methods such as the steady-state hot plane method and the flash method. The results showed, in addition to the lightness offered by peanut shells to these composites, that the thermal conductivity and thermal diffusivity vary respectively from values 0.623 W.m−1.K−1 and 4.8 m2.s−1 for raw clay to the values 0.323 W.m−1.K−1 and 3.5 m2.s−1 for the mass fraction of peanut shells to ϖ = 9%, which give this material the quality of the insulating walls.
Sorption of contaminants into thermoplastic pipes: A Critical Review
Authors: Elamine L. , Elmaliki A. , Majid F.
Published: April 2020

For several decades, polymeric materials are increasingly used in various fields, particularly in the distribution of drinking water thanks to the various advantages represented by polymers such as light weight, low cost, easier to install and without any problem of corrosion compared to metal pipes. One of the main concerns of researchers is the sorption of the constituents of drinking water through the pipe. Many studies have found that the mass transfer of a liquid into the polymer has consequences such as the change of crystallinity, the yellowing of the polymer, decrease of mechanical resistance and the swelling of the polymer. The aim of this study is to carry out a review about the sorption of the constituents of liquid transported into the material in order to summarize what is already done in this field. We started with the theoretical study of sorption then the experimental one by showing the different methods used to measure the diffusivity of a contaminant towards the polymer then we enumerated the empirical and analytical models developed for predicting diffusivity and solubility coefficients and finally we showed the influence of this transfer on the mechanical characteristics and the morphology of thermoplastic pipes.
CFD Simulations and experimental investigation of nucleate pool boiling of liquid nitrogen
Authors: Bouazaoui Kenza , Agounoun Rachid , Kadiri Imad , Sbai Khalid
Published: April 2020

Pool boiling heat transfer is a very efficient mode of heat transfer. It is used in various energy conversion and heat exchange systems and in the cooling of high energy density electronic components. In this work, heat transfer during nucleate boiling for a brass ribbon horizontally immersed in liquid nitrogen is experimentally and numerically studied. An experimental apparatus was built to conduct a pool boiling heat transfer study. The capabilities of Computational fluid dynamics (CFD) boiling model in pool boiling heat transfer is investigated. The computational model used combines the Euler/Euler two-phase flow. The general measurements of the super-heat, the influences of super-heat on the triggering of the boiling, as well as the critical flux which represents an important issue for the security of the systems were analyzed. The results of numerical simulations were compared with experimental data.
Infrared-Active Modes in Finite and Infinite Hexagonal Boron Nitride
Authors: Boutahir Oussama , Lakhlifi Souhail , Boutahir Mourad , Fakrach Brahim , Rahmani Abdelhai , Chadli Hassane , Rahmani Abdelali
Published: April 2020

In this theoretical paper, we study the Infrared spectra of h-BN as a function of their lengths. Calculations are performed in the framework of the force constants model, using the spectral moments method. This original approach allows us to consider not only infinite h-BN sheet as usual in most theoretical models but also h-BN sheet with finite lengths. These predictions are useful to interpret the experimental data.
Effect of the integration of hemp wool as an insulation material for the construction of the roof and external walls of a typical Moroccan building
Authors: Dlimi M. , Agounoun R. , Kadiri I. , Sbai K. , Rahmani A.
Published: April 2020

This paper deals with the integration of thermal insulation in Moroccan buildings roofs and external walls in order to reduce energy consumption due to the use of air conditioning systems. The insulation material under investigation is the hemp wool, an ecofriendly material whose use allows the storage of the Carbone and help reducing greenhouse gas emissions. In order to assess the dynamic thermal performance of the typical Moroccan insulated building, a life cycle cost analysis is conducted based on annual cooling transmission loads specific to the climate of Meknes, Morocco. Optimum insulation thicknesses, energy savings and payback periods are determined for a building life-span of 20 years. Investigations are carried out based on an implicit finite difference method using a home-made code developed in Matlab.
Prediction of flexural strength of natural pozzolana and limestone blended concrete using machine learning based models
Authors: Wang Xiao-Yong
Published: April 2020

Natural pozzolana and limestone ternary blended concrete is a new type of limestone calcined clay cement (LC3) concrete. Natural pozzolana and limestone can benefit each other and contribute to the performance improvement of concrete. Flexural strength is an important engineering property of concrete. This study predicts the development of flexural strength of ternary blended concrete using machine learning based models, such as artificial neural networks (ANN) and gene expression programming (GEP). Concrete mixtures and curing ages are used as input parameters of ANN and GEP. Flexural strength is output parameter of ANN and GEP. The correlation coefficients of GEP and ANN model are 0.98 and 0.99, respectively. GEP and ANN can make reliable evaluations of flexural strengths of ternary blended concrete.
Tensile strength of multi-angle composite laminate scarf joints with FEM
Authors: Roy R , Kweon J-H , Nam Y
Published: April 2020

This study focus on the tensile strength of angle-ply composite laminate scarf joints and corresponding finite element modelling (FEM) methods. Tensile tests are performed at 25°C and 75°C on scarf joint specimens with unidirectional laminate stacking sequences. The joint tensile strength result values at 75°C represent around 86% of those obtained at 25°C. The tensile test is simulated with finite element modelling including cohesive elements to model failure. The joint adhesive film is represented either with only full thickness cohesive elements, or with thin or zero-thickness cohesive elements combined with solid elements having a plastic adhesive material model. Simulations results show that in the case of a unidirectional laminate, the adhesive modelling method had less than 1% effect on the simulated tensile failure strength. For quasi-isotropic laminates with a given ply angle count but of varying ply order, the simulated tensile failure strength varies up to 15%, which confirms tendencies reported in the literature.
Temperature Stable and Low Loss Microwave Dielectric Ceramics of Li2Mg3-xSrxTiO6
Authors: Shi Xiaolei , Zhang Huaiwu , Zhang Dainan
Published: April 2020

In this paper, a series of Li2Mg3-xSrxTiO6 (x = 0, 0.02, 0.04, 0.06, 0.08) ceramics were prepared by the conventional solid-state reaction method. The effects of Sr2+ substitution on the structure, morphology and microwave dielectric properties of Li2Mg3TiO6 ceramics were investigated. The X-ray diffraction (XRD) results indicated that Li2Mg3TiO6 and SrTiO3 phases stably coexisted with each other and formed composite materilas. The appearance of porous structure mainly originated from the volatilization of lithium at high sintering temperatures. As the Sr2+ content increased from 0 to 0.08, the optimum dielectric constant (ε

r
) increased from 13.61 to 17.32, the quality factor (Q×f) decreased monotonously and the temperature coefficient of resonant frequency (τ

f
) changed from -34.4 to +16.8 ppm/°C. The variations of ε

r
, Q×f and τ

f
could be explained by the Lichtenecker logarithmic model and mixing rule, respectively. In particular, optimal microwave dielectric properties of ε

r
= 16.08, Q×f = 82100 GHz, τ

f
= +1.7 ppm/°C were obtained for Li2Mg2.94Sr0.06TiO6 ceramic sintered at 1310 °C for 5h.
An Application of Failure Mode, Effects and Criticality Analysis (FMECA) for Composite Structures of Airplanes’ Wings
Authors: Wang Qiang , Xia Ruicong , Liu Qiuhan , Hu Qiuping
Published: April 2020

Composite structures have played a significant role in enhancing airplane’s performance However, defects inside can be a potential threat to flight safety. To resolve the hazard. FMECA was applied to the defect analysis of composite structures on airplane’s wing. And the failure mode of the highest criticality was found to be the impact damage. Then impact test on typical composite laminates was carried out. The caused damage was qualitatively analysed and proved impact of low energy brings latent risk. Practical solution was put forward to improve the safety or reliability of the applied composites in the airplane.
A method of measuring the arc radius of Rockwell diamond indenter
Authors: Yuanyuan CUI , Ming YE , Feng Zhang , Jiping Liu
Published: April 2020

Rockwell hardness is the most widely used hardness measurement method in industry at present. Taking superficial Rockwell primary standard machine in National Institute of Metrology(China) as an example, the uncertainty caused by the radius of the indenter arc accounts for 50% of the total uncertainty. In view of the important influence of the arc radius at the top of Rockwell diamond indenter on the evaluation of Rockwell hardness uncertainty, a profile projection system is established which is composed of lens, industrial camera and area-source of light. After pictures are obtained with camera, the next task for these pictures is to be calculated to get target parameter. The target parameter is obtained by profile extraction and radius calculation. In this paper, a new method is proposed as an algorithm criterion that sum of absolute value of data points and fitting arcs is used. Simplicity algorithm is introduced to iteratively solve the algorithm criterion. The purpose of using the algorithm is to eliminate the influence of outlier noise points. To verify the validity of the method in this paper, we conduct a series of experiments. The traceability experiment with standard sphere shows that the expanded uncertainty of the system of the instrument can achieve1.0µm,k=2.The uncertainty of measurement result with Rockwell diamond is1.5µm,k=2. The method in this paper bases on a simple-structural system, has high measurement accuracy, and can be used for rapid screening, evaluation, verification and calibration of Rockwell diamond indenters in industry.
Online fatigue damage evaluation method based on real-time cycle counting under multiaxial variable amplitude loading
Authors: Xue Long , Shang De Guang , Li Luo Jin
Published: April 2020

To realize on-line multiaxial fatigue damage evaluation for the servicing mechanical components, a real-time multiaxial cycle counting method is proposed, meanwhile, an online multiaxial fatigue damage evaluation method based strain-critical plane model is given and validated by the fatigue experimental data of En15r steel. Investigation showed that the proposed on-line multiaxial fatigue damage evaluation method could provide satisfactory evaluation results, and the real-time performance of the proposed cycle counting method is path-dependent.
Structure Design of Detachable Knotter mouth and Its Fatigue Performance Analysis
Authors: Cen Hai-Tang , Song Yu-Wei , Wei Rui-Tao , Li Ling , Qin Jian-Guo
Published: April 2020

Knotter mouth is the key part of the knotting on the knotter. Under the action of variable amplitude cyclic load, such as extrusion, shear, torsion and so on, the surface wear of knotter pliers and the fracture of clamp hooks are easy to occur. It takes a long time to disassemble and assemble the knotter mouth, which seriously affects the field operation efficiency of the square baler. In view of the present situation that the knotter mouth of D-type knotter is easy to fail and difficult to replace, on the premise of not affecting the normal knotting function of the knotter, the detachable knotter mouth is designed and completed by reasonably designing the thread structure and rotation direction of the knotter mouth. The disassembly and assembly time is significantly reduced, which is beneficial to the continuous operation of the square baler. ANSYS simulation analysis shows that, compared with the original knotter mouth, the maximum equivalent stress and maximum equivalent strain of the detachable knotter mouth are increased by less than 3%, and the maximum impact fatigue life of the detachable knotter mouth is 60 000 times. The fatigue life of the knotter mouth is much lower than that of the original knotter mouth, but it can still meet the rated life requirements of 40, 000 knotting times of the knotter. The research content makes full use of the safety margin of the knotter mouth structure, which has reference value for facilitating the maintenance and replacement of the knotter mouth and improving the operation efficiency of the whole machine.
Life Cycle Cost Analysis of Gas Turbine Air Inlet Filtration System
Authors: Bai Yunshan , Hao Jiangang , Tian Xin
Published: April 2020

As an important component of gas turbine, air inlet filtration system is of great significance for ensuring the normal operation of gas turbine. However, it is often difficult to select a suitable air inlet filtration system according to the operating characteristics of the unit and the external environment due to the large number of variables. From the perspective of life cycle cost, the main factors to be considered in the selection of inlet filtration system are discussed, and the corresponding calculation model is proposed. Through the cost calculation of a gas-steam combined cycle unit’s inlet filtration system during the whole life cycle, the influence of the initial cost, operation cost, maintenance cost and gas turbine performance degradation cost on the total cost is analyzed. The results show that the cost of gas turbine performance degradation accounts for 90.44%, and the initial cost only accounts for 0.62% in the total cost. Therefore, in the selection of the inlet filtration system, the system economy should be evaluated from the perspective of full life cycle cost. The calculation model has important guiding significance for the selection and cost calculation of the gas turbine inlet filtration system.
Multifunctional smart crib design
Authors: Xie Honghui , Sun Runxi , Yan Zhaojin , Wu Zhilin , Ni Weichuan
Published: April 2020

The environment for newborn babies is harsh, and it is often difficult for parents to understand whether the baby’s current environment is comfortable. Taking care of babies is the most troublesome thing for young parents. In order to let parents know more about the environmental changes around the crib, when the environment changes greatly, timely treatment, such as the temperature difference between day and night when the seasons are alternating, it is difficult for parents to grasp whether the current temperature of the crib is comfortable, and the baby often has a fever due to sudden changes in temperature at night. Through the use of various sensors to collect the surrounding environment of the crib, real-time monitoring of the temperature, moderate, gas and other environmental data around the crib, through the infrared temperature measurement module to measure the baby’s body temperature in real time, while adding music playback, shaking comfort, baby crying detection By uploading data to the cloud through the Internet of Things Internet of Things, parents can easily view the real-time status of the baby’s growing environment, providing a healthy, scientific, and comfortable environment for babies while reducing the burden on busy parents.
A reliability growth projection model based on similar failure mechanisms
Authors: Li Zhongsheng , Fan Jinwei , Chen Dongju
Published: April 2020

Reliability growth test is a common method to evaluate complex electromechanical systems in mechanical engineering. Reliability growth models are usually used to predict the reliability index of systems after the reliability test. AMSAA (army materials systems analysis activity) projection-model-stein (APMS) model is widely used for delayed corrective strategy, since it only requires limited assumptions but covers all failure data. However, there is a controversy about whether the Stein factor introduced in this model is reasonable. To alleviate the problem, an APMS development model is presented in this paper, because different types of parts have different inherent failure mechanisms. The study showed the projection results of the proposed model are credible. Moreover the Stein shrinkage factors were more reasonable and acceptable, as they were derived from the components with similar inherent failure mechanisms. These provide a technical foundation for the wide application of the proposed model.
Head gimbal assembly automated visual inspection by using digital image processing
Authors: Jaturawichanan Phonlawut , Tangjitsitcharoen Somkiat
Published: April 2020

This paper presented an approach of Digital Image Processing (DIP) and measurement properties of image region for inspecting the part in Head Gimbal Assembly (HGA) process. Current, the inspection process is performed by the skilled employee, which depends on employee experiences. The inspection method proposed by using digital image processing to do an image enhancement in order to detect the abnormalities and defects on part. The measurement properties of image region is proposed to identify the abnormality occurred on HGA part after image enhancement, in production process. This research aimed to develop the algorithm to inspected HGA part by considered the number of pads, convex area value, and eccentricity value. Then used measurement properties of image region to enhance the algorithm for classifying part in production process. This approach has been developed and proved with the real part in HGA production process. It’s proved that the algorithm and method proposed can be classified the part in HGA production process.
Discussion on the recycling ecological chain and commercial model of decommissioned batteries
Authors: Yin Juanjuan , Pan Mingyu , Chen Zhen , Li Jing
Published: April 2020

When the battery capacity is reduced to less than 80%, it is no longer suitable for electric vehicles, if the decommissioned batteries directly scrapped treatment, it will cause a great waste of resources, and even cause environmental pollution. The reuse mode of lithium battery can be divided into two modes: Cascade utilization and recovery. This dissertation introduces these two methods, summarizes the current situation of power battery reuse, draws on the successful experience domestic and foreign, and combines the actual situation of domestic enterprises to improve the reuse ecosystem and business model of decommissioned batteries. The paper puts forward the business model of ‘Internet + Recycling Network + specialization processing’, and constructs the closed-loop network of retired power battery recovery, which integrates government supervision, enterprise operation and consumer participation.
Research on electromagnetic radiation interference of high voltage pulse device
Authors: Xu Yuheng , Zhang Xiangjin , Wang Ruibo , Yue Lianyong
Published: April 2020

In view of the strong electrostatic field interference caused by the miniaturization of high voltage pulse capacitor circuit, the protection method of electronic equipment under the strong electrostatic field interference of high voltage pulse device is proposed. Based on the background of miniaturization of all electronic security system, a high-voltage capacitor pulse discharge model is established. The surrounding radiation of high-voltage capacitor instantaneous discharge is simulated by using the COMSOL software. The electromagnetic radiation interference of high-voltage capacitor to the system is analyzed, and the anti-radiation interference measures are proposed based on the electromagnetic shielding mechanism. It provides a basis for the actual circuit design and structure layout, and provides a reference for the stability and safety of the electronic security system and further miniaturization development.
Force Analysis of Fork Type Connecting Structure Pin Roll of Aircraft Vertical Tail in Comprehensive State
Authors: Xing Tianle
Published: April 2020

Aiming at the stress problem of pin roll connection at the vertical tail of aircraft, the thesis establishes a simplified simulation model of vertical tail. From the mechanical perspective, it takes into account the gravity, assembly force of interference fit and the influence of air resistance on the fork force. Compared with the yield stress of titanium alloy material used in the actual fork, it is concluded that actual stress is much smaller than the yield stress of the material, which verifies the rationality of pin roll design.
Research on Improvement Methods of Automotive NVH Performance
Authors: Liu Xing
Published: April 2020

The performance of automotive NVH will directly affect the production and sales of automobiles. This article summarizes the generation and control of the main NVH problems in automobiles, and discusses the methods to improve the NVH performance of the vehicle from three aspects: free damping treatment of the body structure, analysis of the contribution of body panels, and analysis of key hard-point forces of the vehicle steering system.
Study on Test of Color Fastness to Rubbing of Textiles
Authors: Lei Zhenyu
Published: April 2020

The textile sample is rubbed with a dry friction cloth and a wet friction cloth respectively to evaluate the staining degree of the friction cloth. The tester for color fastness to rubbing provides two sets of test conditions through two friction heads of optional sizes: one for pile fabrics; The other is used for monochrome fabrics or large-area printed fabrics. Through the analysis of the original test method, the existing problems and defects of the original test method are obtained. A substitute material is used on the tester platform for testing samples, and the fixation method of the tester’s samples is improved in a pawn type, so as to solve the problem of uneven staining of friction cloth caused by uneven surface of friction head or friction medium and unilateral wear during friction.
Brittle-Plastic Properties Evaluation of Rock based on Element Logging
Authors: Li Yi , Zhang Yan Qi , Hu Zong Min , Geng Chang Xi , Yuan Bai Yan , Li Hao , Ligang Zhang
Published: April 2020

Rock brittle-plasticity is an important factor which can influence the selection of rock breaking method and fracturing layers. It is very important to build up an appropriate brittle-plasticity characterization method and prediction method. In this paper, the point load method was used to test the deep rock load-displacement curve in Songliao basin, calculate the plasticity coefficient and the brittle-plasticity. Then the element content of the corresponding rock samples was tested. The relationship between plasticity coefficient and element content were estimated, and the influence of elements on brittle-plasticity of rocks was revealed. Finally, the calculation model of rock plastic coefficient based on element contents was built up. The research results can be used to evaluate the real-time brittle-plasticity of formation by using element logging data.
Analysis of the influence of the vane width on the fluid transmission performance in the vane-type tank
Authors: Zhuang Baotang , Li Yong , Pan Hailin , Rui Wei
Published: April 2020

Fuel tanks are a core component in satellites that manage the propellant. This study numerically analyzed the fluid transport with parallel guide vanes in a vane type surface tension tank. In this paper, the numerical simulation analysis is carried out for the fluid transmission performance of the parallel vane of the new generation plate surface tension tank, and the influence of vane width on the transmission performance of vane is studied. The results show that, in the whole capillary flow stage, the liquid flow rate increases with the increase of the width a of the guide plate.
Laser Trimming Method for Reducing Frequency Split of Cylindrical Vibrating Gyroscope
Authors: Hu Youwang , Zhong Hongmin , Lu Yunpeng , Duan Ji’an , Sun Xiaoyan
Published: April 2020

Frequency split is the frequency difference between the driving mode and sensing mode of a vibratory gyroscope, which significantly influences the performance of cylindrical vibratory gyroscopes. In order to reducing frequency split, a method of trimming by drilling micro-holes through laser has been introduced in this paper. Firstly, the processing method of the trimming hole is determined by the finite element simulation, and then the feasibility of the method is verified by the experiment. In the experiment, the frequency split of gyroscope is reduced from 2.090Hz to 0.119Hz.
Cosine Gear Planetary Transmission with Small Teeth Number Difference
Authors: Si Chuanrui , Chen Zhitong , Zhang Hongyao , Zhang Yun , Cui Chuanhui
Published: April 2020

This paper presents a model of cosine gear planetary transmission with small number teeth difference (CG_PTSTD). Firstly, the mathematical model of the CG_PTSTD is established based on the theory of engagement, including the equations of the conjugate internal gear and the meshing line. Then an example of the CG_PTSTD is developed. In this example, the 2D and 3D models of the CG_PTSTD are established, and the bending and contact stresses are analyzed by finite element software ABAQUS. The results show that the cosine gear can be successfully applied to the PTSTD without tooth tip interference and there are multi teeth simultaneously participating in the mesh.