bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental Protection Requirements of Power Transmission and Transformation Project Construction Based on Internet of Things Technology and Its Change Trend Analysis
Authors: Zhai Xiaomeng , Cheng Xi
Published: March 2020

Due to the in-depth development of the Internet of Things, various industries have to attach importance to its construction. Based on the advantages of the Internet of Things that can realize intelligent identification and management, the Internet of Things has become another breakthrough after computers, the Internet and mobile communication networks. Based on a comprehensive analysis of the current situation of environmental protection management at home and abroad, the main environmental impact factors in the construction process are analyzed, and a monitoring method of environmental protection measures in the construction process of power transmission and transformation projects based on Internet of Things technology is proposed. The monitoring system of environmental protection measures shall be constructed in full connection with environmental assessment and completion acceptance, so as to improve the level of environmental protection supervision during the construction of power transmission and transformation projects. On the basis of implementing the scientific development concept, accelerating the adjustment of energy structure and accelerating the optimization of power structure, it will become the focus and direction of scientific development of power transmission and transformation systems to adhere to the sustainable development strategy, build a harmonious society, and strengthen environmental protection while developing power engineering construction.
Research on Electricity Market Transaction Model under the Background of Big Data
Authors: Mu Yicheng
Published: March 2020

With the advancement of electricity market reform and the influence of new entities, electricity market transactions have formed a diversified development trend, which puts forward higher requirements for transaction technology support systems. In the trading market a few days ago, power producers participated in the bidding of electricity generation. The trading center gave the optimal trading plan and settlement price under the condition of satisfying the safety constraints of the power grid according to the published competitive load curve and the declared data of power generation companies. The commodities traded in the electricity market are electric energy and various services necessary for the realization of electric energy trading, so the trading in the electricity market is very different from the traditional generation plan. Only by establishing the bidding trading plan model of the trading center can the trading plan be carried out, thus forming the power purchase plan for the power generation company. This paper analyzes the basic sources and characteristics of big data in the power market, obtains the characteristic values of big data attributes of mutual benefit and win-win of both parties through the model, and realizes the visualization of transaction price.
Research on Fault Diagnosis Method of Rolling Bearing
Authors: Zhou Huan , Wang Hao
Published: March 2020

Rolling bearings are often used as supporting parts in mechanical equipment. Its damage will often lead to the damage of related parts, resulting in the failure of the whole system and leading to shutdown and other accidents. From the point of view of diagnosis technology, rolling bearing is the key part of rotary machinery and the main object of monitoring and diagnosis. The reason for rolling bearing fault diagnosis is to ensure reliable operation of the bearing under various working environments, thus ensuring the working accuracy of the whole machine. When some component of the bearing works and produces defects, the bearing signal measured by the acceleration sensor has the characteristic of periodic impact. In this paper, the basic characteristics of bearing fault signals are analyzed, and the method of extracting fault symptoms of rolling bearings from vibration signals is discussed.
Design of Embedded Terminal Data Remote Transmission Control System in Internet of Things
Authors: Fu Weiqing , Yang Minglai
Published: March 2020

The underlying data exchange system of the Internet of Things is an integrated system for data collection and information transmission of the Internet of Things. The design method of the underlying data exchange system of the Internet of Things based on embedded is proposed. The embedded data remote acquisition system designed in this paper, the main communication control module and data acquisition and processing module are relatively independent. The embedded microcontroller AT89S52 is used to realize the main data transmission function. In the hardware design, the selection of A/D analog-to-digital converter is fully considered. A scheme of remote monitoring system based on the combination of communication network and Internet is proposed, and an embedded system based on DSP chip is further selected to design and implement the data transmission terminal of the remote monitoring system. Combined with Visual DSP++4. 5 development platform, the integration processing and information processing of the Internet of Things bottom data are carried out. The VIX bus transmission foundation is adopted to realize the data exchange control of the Internet of Things bottom, and the hardware design and software development of the system are completed. The test results show that the stability of data exchange at the bottom of the Internet of Things is good and the output error rate of data exchange is low.
Reasonable distribution of electric vehicle charging stations
Authors: Zhang Tingxuan
Published: March 2020

With the depletion of petroleum resources and people’s attention to environmental issues, the electric vehicle industry is booming. However, due to limitations in charging technology, the charging speed of electric vehicles cannot be completely satisfactory. Therefore, this paper proposes an innovative charging station location model to meet the needs of consumers. Due to the shortcomings of the traditional coverage model, the proposed location model consists of a loop model and a generalized maximum coverage model combined with a cellular network model. After the simulation experiment of the model in Ireland, we obtained the experimental results. Our proposed location model improves the utilization of EV charging stations.
Joint sleep staging model based on pressure-sensitive sleep signal
Authors: Huang Yongfeng , Liang LiWei
Published: March 2020

Sleep quality is an important indicator of human health, and sleep staging is a prerequisite for assessing sleep quality. In this paper, the CNN-BILSTM sleep staging model is proposed based on the pressure-sensing sleep signal collected by the smart mattress. The CNN network is used as the feature extraction part for the problem of the traditional sleep staging model in the pressure-sensing sleep stage [2]. This part can automatically extract the pressure sense. The staging characteristics of the sleep signal, combined with the BiLSTM model for sleep staging. In the experiment, the sleep data of 11 different experimenters based on smart mattress collection were used to identify the three sleep stages, in order to verify the superiority of the sleep stage of the model [3]. Two kinds of contrast experiments were used, one was compared with a single CNN stage, the BiLSTM model was compared, and the other was compared with the traditional feature extraction based sleep stage model. The experimental results show that the model has an accuracy of more than 80%. Better than traditional sleep staging and single deep learning sleep staging program.
Block Chain Financial Transaction Using Artificial Neural Network Deep Learning
Authors: Zhao Bowen , Wang Runyu , Cai Yan , Zhao Enyu
Published: March 2020

In order to adapt to the rapid development of the trading market in the financial industry under the condition of artificial intelligence and solve the unstable problem of capital loss in the process of financial transactions, in this study, firstly, the concept and principle of block chain are summarized, and the problems that block chain can solve are analyzed in an all-round way. Secondly, the concepts and computational principles of artificial neural network and deep learning are analyzed, and they are integrated into block chains for artificial intelligence payment. Finally, the block chain, which integrates artificial neural network and deep learning, is applied to the financial market. The results show that block chains can make use of decentralized networks to simulate virtual consumer payments, and can be used in many financial fields. They can track and check information and prevent goods from being tampered with in the logistics process. Artificial neural network (ANN) can imitate the human brain to process and calculate the captured data by using neurons in both forward and reverse transmission modes. Deep learning can process and recognize graphics and language information by means of computer network. After updating the artificial neural network and the block chain of deep learning, all kinds of transaction needs can be met through appropriate calculation methods, so as to accurately grasp the trading situation of financial market and provide the standard data of artificial intelligence to customers. This shows that the block chain which integrates artificial neural network and deep learning plays a decisive role in financial transactions, can bring huge potential benefits to the financial industry, and make the financial transaction market develop steadily under huge competitive pressure.
Existence design of output feedback H
∞ system compensator
Authors: Shi Xiurong
Published: March 2020

This paper is concerned with the existence design of output feedback H
∞ system compensator. Based on the current and historical research status, a novel compensator for H
∞ interference attenuation is developed by the method of linear matrix inequality for the purpose of reducing the harm to the system. The aim of this paper is to design the compensator such that the closed-loop system is stabilization and the prescribed H
∞ disturbance attenuation performance is achieved.
Construction of smart city evaluation system based on big data
Authors: Cheng Qian , Li Xiaolong
Published: March 2020

Big data makes data sharing possible. The existing database of the government management can realize efficient interconnection, greatly improve the collaborative office capacity of all departments of the government, improve the efficiency of serving the people, and greatly reduce the cost of government management. The most important thing is to provide strong support for government decision-making. His continuous “wisdom” will promote the smart city to be more intelligent and more intelligent. Scientific and more efficient goal. Based on the principle of wisdom, this paper first analyzes and selects 25 important indicators from the four aspects of environment, economy, society and population to establish the indicator system of sustainable urban development; then establishes the evaluation model of urban intelligent growth, and uses the size of the comprehensive index to measure the degree of urban development wisdom. Taking Xi’an as an example, the comprehensive index of the city based on the current development plan is obtained by using the urban smart growth evaluation model, and a new development plan is made for the city by using the urban smart growth evaluation Introduction.
Research on algorithm recommendation mechanism and characteristics of personalized news app——Taking “Toutiao” as an example
Authors: Yuan Yuan
Published: March 2020

With the development of mobile Internet, new technologies such as algorithm distribution and personalized recommendation came into being. The media appeared intelligent trend and the era of intelligent media came. This article uses China’s most popular algorithm to push news app “Toutiao” as an example. The app’s recommendation system is analyzed from the basic principles of algorithm recommendation, text recommendation and personalized tag. For news app, algorithm push is an inevitable trend, and the principle of algorithm recommendation mechanism of Toutiao is studied and beneficial. The platform regulates its own behavior and explores the solution for further development.
Numerical Simulation of Elbow Erosion in Liquid-Solid Two-Phase Flow
Authors: Xie Dingkun , Wu Yurong , Zhang Zhaolun , Wang Tengru , Chen Puxin , Cui Yu , Li Ce , Feng Shenyang
Published: March 2020

In order to study the erosion and wear of elbows caused by solid-liquid two-phase flow, CFD numerical simulation of elbows with different geometric parameters was carried out based on hydrodynamics and tribology theory. The rules of geometric parameters and wear rate of elbows were summarized, and the wear mechanism of pipelines was analysed with related theories. The main conclusions are as follows: the maximum erosion rate decreases with the increase of the pipe diameter and bending angle and increases with the increase of the pipe length and bending radius. Among the above factors, the bending angle has the greatest impact on the maximum erosion rate of the pipeline.
Analysis of arch bridge collapse based on finite element technology
Authors: Niu Yu , Yang Qingshun
Published: March 2020

Even in today’s technologically advanced, engineering accidents are still unavoidable. How to numerically simulate the collapse process of bridges becomes a major problem, and the continuous development and maturity of finite element technology provides an effective way to solve this problem. This paper takes the Yilanao Bridge in Taiwan as the research object, and establishes multiple models based on the finite element analysis software MSC. MARC and MIDAS, and analyzes the causes of the damage. This paper has certain reference significance for the study of the failure form and failure process of arch bridges.
Strength properties and reinforcement mechanism of bio-enzyme stabilized marine soils
Authors: Li Jinzhu , Wang Wenjun , Huang Hongxiang
Published: March 2020

Bio-enzyme was used to stabilize the marine soils of Ningbo. Strength tests, XRD tests and SEM tests were used to analyze the strength and microstructure properties of bio-enzyme and cement stabilized soil. The results of strength tests show that the bio-enzyme not only has obvious reinforcing effect when added alone, but also can promote the solidification of cement. The results of XRD tests show that there is no new substance formation during the solidification process when only bio-enzyme added, which indicates that the process is a physical effect. The results of SEM tests show that the bio-enzyme can improve the pore arrangement, pore morphology and pore size of the soil, and reduce the directional fractal dimension, probability entropy, porosity fractal dimension and pore shape fractal dimension, which makes the orientation of the pores better, the order of the particles higher, the pore size more uniform, and the degree of particle agglomeration higher, therefore increasing the strength. In all the microstructure parameters, the fractal dimension of pore morphology has the greatest influence on the strength of stabilized soil, that is, promoting the aggregation of soil particles is the main role of bio-enzyme in improving the strength of stabilized soil.
Research on the framework of full-process condition monitoring and evaluation method for express logistics based on multi-information fusion and intelligent identification
Authors: Ma Luping , Zhang Yuan , Du Yanping , Huang Lei
Published: March 2020

This paper describes the background and significance of the whole process state monitoring of express logistics in the three aspects of environment, society and economy, then introduces the current status of the tracking and monitoring of logistics process at home and abroad, and proposes the method of full-process condition monitoring and evaluation method for express logistics based on multi-information fusion and intelligent identification, The content of the method mainly includes: collecting data based on various information collection methods such as sensors, extracting and identifying the characteristics of expressive behavior through the algorithm and quantitative evaluation of the whole process express logistics status.finally, Finally, the paper summarizes the whole system-based method of multi-information fusion and intelligent identification of the whole logistics process monitoring and evaluation, and explains the follow-up work direction and content.
Self-absorbed Ca doublet lines for stand-off quantitative analysis by laser induced breakdown spectroscopy
Authors: Zhao Na , Qian Jing , Cai Jiansi , Zhang Hongyan , Wang Menghan
Published: March 2020

Laser induced breakdown spectroscopy (LIBS) is one of the promising techniques for stand-off detection of element composition. However, it is somewhat limited by quantitative shortage. Absolute line intensity may be influenced by acquisition conditions, environmental variation, and sample surface conditions. Relative intensity may also fluctuate greatly. This study shows that the intensity ratio between Ca II doublet emission lines (393.37 nm and 396.85 nm) is stable, and changes with Ca concentration (or Ca atoms count within the laser spot). This is due to differences in self-absorption between the two transitions. A theoretical calibration shows a linear section for low species density and quadratic section for high species density. Experimental results confirm the linear section after density correction of CaO pellets. However, an equipment factor should be considered for numerical calibration in different laboratories. For Ca-containing samples, quantitative analysis could be based on the detected Ca spectrum. Ca is also shown to be suitable as an internal standard reference to determine other elemental concentration, such as Mg.
Research on Human-Computer Interaction Design of Office Chair Based on QFD Method
Authors: Wang Zhenyu , Chen Ming , Lyu Jianhua , Chen Siyuan , Chen Yuting
Published: March 2020

Based on quality function deployment (QFD) and emotional design theory, the psychological needs of users are explored, and the interactive design system of office chairs is developed centering on users, thus solving the problems of space efficiency, office mode and human-computer interaction. First of all, through the relationship between the emotional concept and “function-behavior-benefit” in QFD method, from the perspective of emotional experience, the man-machine relationship is analyzed, and the principles and methods of contemporary office chair comfortable and healthy experience design are summarized. Secondly, based on the product structure and human-computer interaction design, the internal demand of consumers is transformed into the actual demand of products, and the QFD house of quality model is output to obtain the best design scheme. Finally, through design demonstration, the integrated application of emotional design and QFD method is feasible and effective, which can form a mapping relationship between product benefits and user needs, thus realizing the man-machine interaction design of multi-adaptive office chairs.
Study of the types and characteristics of geological hazards in reefs of Nansha Waters, South China Sea
Authors: Guo Lei , Qian Jing , Lei Chengbin , Cai Yihuang , Zhao Hongjuan
Published: March 2020

Reports of the 19th National Congress of the Communist Party of China identifies that the construction of islands and reefs in South China Sea (SCS) has been actively promoted. It is of great practical significance to study the types and characteristics of geological hazards in Nansha Islands and reefs, and it is the precondition and guarantees to carry out the construction of islands and reefs. At present, the research on marine geological hazards in China focuses on oil and gas enrichment areas such as Bohai bay, southern Yellow Sea and Northern of South China Sea, and there is little research on southern of South China Sea, especially Nansha Reefs. On the basis of collecting and sorting out previous research achievements, combining with existing geological and geophysical data and drilling data, his paper focuses on analysing two single-channel seismic profiles N01 and N02 collected by “Shiyan 2” of South China Sea institute of Chinese academy of sciences in Nansha Islands and reefs in 2013, and studies the types and characteristics of geological hazards in this area. The study shows that the whole Nansha block belongs to areas with weak seismic activity, most of the faults in the island reef area are weak and micro-active, and the volcanic activity in the island reef area is weak, and the coral reef growth rate is fast, which can be suitable for all kinds of engineering construction projects.
Research and development of icon recognition system based on machine vision
Authors: Cao Ning
Published: March 2020

Machine vision represented by two-dimensional code and barcode is widely used, but both are not friendly enough for human eye recognition and cannot be used in human-machine collaborative work. Therefore, this paper proposes a machine vision-based icon recognition system that can quickly identify human-friendly icons. The system first converts the real-time image captured by the camera into binary image. Secondly, divide the binary image into 9*9 cells, get the binary information of each cell center point, match with the template information, and finally judge and draw the recognition conclusion. Experiments show that the method is fast and accurate in identifying icons, and the effect is good.
Study on Water Hammer Protection of Accumulator for High Pressure Water Descaling System
Authors: Meng ShengLi , Chen Xiao Bing , Yao Weiguo , Che Congbin
Published: March 2020

Use characteristic linear method to establish the general mathematical model of the protection calculation of accumulator from water hammer in high pressure water descaling system pipeline. Through the model, the paper calculated the change of transient water hammer pressure in the main pipe under 3 different conditions: with and without accumulator, different accumulator capacity and different accumulator installing positions. The calculation results show that the pressure fluctuation of the main pipe changes with the descaling procedure; the accumulator provides obvious protective effect on the water hammer of the high pressure water descaling system and the initial volume of the accumulator has an obvious influence on the water pressure changes while the installation positions on the main pipe is with little influence on the protection effect of the accumulator.
Simulation of fluid around parallel-column by LES
Authors: Cheng Lei , Zhang Zhenwei , Zhao Xinyu , Zhang Xiaoming
Published: March 2020

To figure out the distributions of the parallel-column’s field, this article used LES to study parallel-column. This article demonstrate the rule of how the parallel-column field changes with P/D (P: center spacing D: diameter), focused on the how the Bluff-body’s P/D affect to the speed field & pressure field. The simulation showed the field changed as the P/D ratio rise, when P/D ratio reach 0.2-0.6 the field show as Von Karman vortices, 0.8-1.0 show as parallel field, when it got large than 1.2 will be show as vortex side flow. The optimum working point is between 0.8-1.0, the air flow in this area’s subgrid Turbulent Viscosity is smaller the vortex strength of tail also weak.
Research and Application on the Power Transmission and Transformation Equipments’ Fault Diagnosis Method Based on Online Monitoring
Authors: Chen Zhaohui
Published: March 2020

How to ensure the safe and stable operation of power system is one of the key tasks that need to be solved urgently in power department at present, and the fault factors such as normal operation and condition maintenance of power transmission and transformation equipment determine the safety of power system. In order to solve the fault diagnosis method of transmission and transformation equipment, improving the efficiency of equipment condition maintenance and improving the ability of fault discrimination is one of the main solutions. In this paper, through the equipment state evaluation and fault early warning based on-line monitoring, a variety of inspection measures are fully considered through the model, so as to predict the equipment with hidden trouble and put forward the fault early warning.
Development of intelligent remote control walking fish robot
Authors: Wu Guoguo , Yang Guolai , Li Chunjiang , Luo Tianhong , Jiang Rongliang , Liao Jiameng , Yang Baojun , Zheng Denghua
Published: March 2020

The design is based on mobile phone platform, with communication technology, design a solution for wireless remote control fish robot. According to the cage mechanism, Arduino control technology and mobile phone APP development technology of bluetooth communication realize the real-time control of the direction of the robot and remote feeding function. The interaction of toy, human and nature not only provides a new idea for the design of remote control ship, but also provides a new direction for the development of remote control toys.
Bim-Based Artificial Engineering Integration Method for Building Engineering Database
Authors: Che Xiaoyang
Published: March 2020

In order to perfect the database system of building engineering and meet the demand of data processing and integration, a BIM - based artificial intelligence system integration research method of building engineering database was designed. The role of artificial intelligence integration method in building engineering database system was deeply analyzed, based on which the effectiveness of BIM based artificial intelligence integration method in building engineering database was further discussed. After experimental verification, the bim-based artificial intelligence integration method of building engineering database was more conducive to further improving the efficiency of architectural engineering, effectively reducing the design cycle of architectural engineering and realizing the optimization design of architectural engineering. And its integration efficiency was about 30% higher than the traditional integration method.
Application of Artificial Intelligence in Quality Test of Vibrating Fruit Harvesting Mechanical Operation
Authors: Yang Xiaozhou
Published: March 2020

Harvesting operations were an important part of the production of fruit. In order to improve the efficiency of harvesting fruit and reduce the cost of harvesting, in view of the small working space in the dwarf dense planting mode of China’s orchard, the artificial intelligence technology was applied to vibrating fruit harvesting mechanical operation, and the theoretical analysis of artificial intelligence technology application was analyzed; The equipment requirements of artificial intelligence in vibrating fruit harvesting machenical operation were studied. On this basis, the system application process of artificial intelligence in the harvesting machenical operation of fruit trees was deeply explored, and the work was carried out in the practice of mechanical operation, and the recovery rate was detected to be 90% to 95%. Tests had shown that the recovery rate was 36% higher than the traditional vibrating fruit harvesting technology.
Application of Multi-Channel Communication Technology in Wireless Sensor Networks
Authors: Guan Wei
Published: March 2020

This paper mainly introduces the application of multichannel communication technology in wireless sensor network. The corresponding solutions are proposed based on the analysis of the structure and characteristics of wireless sensor, and the multi-channel MAC protocol in wireless sensor network. In this paper, multi-channel communication technology in wireless sensor network (WSN) is studied, the existing problems and reasons are analysed, and some solutions to further promote the further development of the technology are put forward. With the wide application of WSN, the security of WSN has been paid more and more attention. In this paper, the existing time synchronization protocol, from the security point of view, and the fault tolerance design of the fits protocol. The protocol has an intrusion detection mechanism, which can detect the attack of malicious nodes in time synchronization. Aiming at the small deviation of slow attack and the problem of time synchronization error, information fusion is based on the quality principle, and according to the time synchronization information of different nodes, we make random weighted average correction for local time nodes. The simulation results show that the fits time synchronization protocol has good intrusion detection and fault tolerance capability.
Submarine Target Recognition Based on Gps Positioning System
Authors: Qiao Weihua , Shoujun LI
Published: March 2020

With the development of transportation and the rapid spread of travel tools, economic exchanges around the world have become more frequent. The Global Positioning System (GPS) is an all-weather, high-precision, wide-coverage electronic navigation device that plays an important role in identifying submarine targets. The key technology of GPS is the real-time accurate extraction of targets, and the essence of target extraction is image segmentation. In order to achieve the purpose of seabed target recognition, a simple and effective method is proposed. In this paper, image points of active target image features are calculated by image processing to achieve positioning of the target. The neural network is used to establish the coordinate correspondence of the target from the image space to the GPS positioning system space to locate the submarine space moving target. Based on the positioning principle of GPS technology, the navigation technology of submarine target recognition is studied. A multi-target detection experiment for submarine target location was carried out. The results show that the multi-target recognition and positioning system based on GPS positioning system combined with sonar image design, the target recognition accuracy rate is over 93%, which meets the technical requirements of the detection system. Improving the identification of submarine targets is important.
Research on GPS Timing Remote Synchronization Algorithm in High Altitude Meteorological Data Acquisition System
Authors: Qiu Min , Qiu Yang , Yang Yurong , Bai Yu
Published: March 2020

The various high altitude meteorological parameter influence each other, and test data of different locations need to be synchronized. In this paper, we propose a GPS timing remote synchronization algorithm for high altitude meteorological data acquisition system, which can make the meteorological data at different locations meet the requirements of synchronization. GPS module uses NEO-M8N chip of UBLOX to achieve GPS timing remote synchronization, which include hardware and software designs for the system. We use the designed system to measure high altitude meteorological data in two different locations, analyze experimental results and show the relationship between meteorological parameters. In the processing for experimental results, we employ Fletcher-Reeves algorithm based on artificial neural network to predict meteorological data, and analyze training errors of the algorithm. The proposed system can realize reception and processing of remote data synchronously, and predict the meteorological data for weather forecast.
Magnetostriction effects in silicone elastomers
Authors: Kelbysheva E S , Valiev H H , Ya Minaev A , Stepanov G V , Korovkin Yu V , Vlasov A N , Karnet Y N , Snegireva N S , Yu Bazin A
Published: March 2020

New silicone magnetoactive elastomers have been synthesized and studied. Significant magnetostrictive effects in the synthesized composites were visualized by microscopy. The obtained results can be the basis for the design of controlled dampers and promising magnetostrictive engines of a new generation with micro and nanoscale positioning accuracy and the ability to transmit significant force effects on the operated objects.
Characterization of flawing on feather surface of low pressure compressor blades from VT-3 titanium alloy
Authors: Kozyreva O E , Volgina N I , Belelyubskii B F
Published: March 2020

The article provides the results of the study of flawing on feather surface of low pressure compressor blades. These defects were identified during flaw-detective etching treatment, and were intentionally, with the help of mechanical and electrical influences. During the study, comparison of the microstructure of the feather surface of blades in the area of identified and specially caused defects was made in order to determine their nature and the cause of their formation.
Classification of viscoelastic models with integer and fractional order derivatives
Authors: Krusser A I , Shitikova M V
Published: March 2020

In the world literature there exists a wide variety of papers devoted to linear viscoelastic models. This work was initiated by the absence of a single generally accepted classification of viscoelastic models. We focused on the basic mechanical models, namely, the Kelvin-Voigt, Maxwell, standard linear solid and Jeffreys models. All other models are different combinations of basic elements connected in series or in parallel. The classification also includes viscoelastic models with fractional derivatives and fractional operators.
Auxetics materials: classification, mechanical properties and applications
Authors: Mazaev A V , Ajeneza O , Shitikova M V
Published: March 2020

In contrast to classical materials, auxetic materials (from the Greek word αὐξητικόσ / auxetikos) possess negative Poisson’s ratios, thereby exhibit reverse deformation mechanism. Under a tensile force applied in the longitudinal direction, auxetics expand in the perpendicular transverse direction. Consequently, auxetic materials possess various useful properties for potential applications. This review contains the classification of auxetic materials according to different criteria: the type of structure, cell geometry and scale, mechanical characteristics, methods of their production, and engineering applications. The aim of this work is to sum up structural information on auxetics.
Classification development for working modules of detail surfaces
Authors: Sakharov A V , Rodionova N A
Published: March 2020

The necessity for the development of a system of interrelated classifications of module surfaces was justified. Main distinctive features, based on which the general classification and the classification of module surfaces are developed, were determined. Examples of the development of the general classification and classification of one constructional types of working surface modules were provided.
Spring-in experimental evaluation of L-shaped pultruded profiles
Authors: Vedernikov A N , Safonov A A , Gusev S A , Carlone P , Tucci F , Akhatov I S
Published: March 2020

Currently pultruded profiles are widely applied as structural elements in different areas due to their high strength, low weight, improved corrosion and fatigue resistance properties. Nevertheless, production of pultruded elements presents challenging aspects related to the peculiarities of pultrusion manufacturing process. Indeed, produced profiles exhibit shape deformations immediately after curing such as spring-in and warpage. These manufacturing induced shape distortions evidence time evolution behavior. This paper presents a seven months long experimental investigation of time-dependent distortion evolution of pultruded L-shaped profiles.
On the issue of resistance of dispersed-filled composites, the development of cracks of mixed type
Authors: Burukin I V , Pirozhkov V A , Rybakova M R , Skvortsov A A
Published: March 2020

Currently, various non-metallic materials are widely used in industry, including composite ones, which have a number of positive properties. The practice of operating products from these materials allows us to conclude that many of these are characterized by a brittle nature of destruction. Moreover, numerous experimental studies have established that the crack resistance of brittle materials is directly dependent on the type of crack opening. In many studies devoted to the study of strength issues, the essential role played by the spherical component of the stress tensor in the development of the process of brittle fracture of the material plays a significant role.
The simulation of crack growth in rolling stock running wheel disk
Authors: Chunin V V , Knyazev D A , Timakov M V
Published: March 2020

The article reviews scientific and technical literature in the field of the survivability of railway wheels. The computer simulation of the flat crack growth at different temperatures is performed with the estimation of the crack propagation rate and survivability parameters. In conclusion, the estimation is provided to refine the calculation model, followed by the recalculation of the obtained results.
Reliability of strain gauge measurements to clarify the strength of structures at high temperatures
Authors: Klymov M V , Maslov S V , Poguliaiko A N
Published: March 2020

The paper considers the problem of ensuring the reliability of experimental data obtained by tensometric studies of existing power plants. A technique that allows taking into account the change in the metrological characteristics of high-temperature strain gauges has been proposed. The design of the installation for determining the sensitivity of strain gages at temperatures up to 700°C has been considered.
Numerical methods for power equipment tube bundles vibrations studying
Authors: Koretsky S A , Fesenko T N , Dronova E A
Published: March 2020

Calculations of the steam generator model tubes are considered. Dynamics calculation research for those tube bundle model was worked out. Displacements, velocities, accelerations and amplitudes root-mean-square values of tubes vibration acceleration functions were determined as well as their dependences on structural and operational characteristics were investigated. The design parameters include: tube spans length, gape size in tubes nodes coupling and spacer grids, tube radius position.
Combined influence of seasonal processes of permafrost soils on stress and strain state of underground oil pipeline
Authors: Naumov O V , Moskvitin G V
Published: March 2020

The paper simulates the condition of the underground oil trunk pipeline under the combined influence of freezing-thawing processes in permafrost soils. Changes in seasonal temperatures lead to the emergence of processes such as heaving and sinkholes, which affect the spatial position and performance of the pipeline.

The paper presents the calculation of the underground pipeline laying in permafrost with an outer diameter of 520 mm (steel 355 JR), a length of 30 m (depth of 1.5 m), which passes oil temperature 25 °C under pressure of 5 MPa, with the temperature of the outer shell of the pipe 0 °C. Simulation was carried out in SolidWorks using the Simulation package. The stress-strain state and displacements arising from the combined effects of processes in permafrost soils are determined. According to the results of the study, conclusions are drawn about the impact of the combined effects of freezing and thawing processes on the performance of the underground pipeline.
Special Rotordynamics: Finite Element Model for Pump Rotor
Authors: Nikiforov A
Published: March 2020

An approach to the finite element modal analysis for the real pump rotor is presented. The first eigenfrequencies and eigenmodes of the initial, simplified and battered rotor-seal-bearing system are compared.
Development of geometrically nonlinear finite element «2-D prismatic joint» using the augmented Lagrangian method
Authors: Nizametdinov F R , Sorokin F D
Published: March 2020

An algorithm for obtaining the stiffness matrix and the vector of elastic forces of a finite element (FE) of kinematic constraints using the example of the geometrically nonlinear element “Two-dimensional prismatic coupling” is proposed in the article. The algorithm is based on the application of the extended method of Lagrange multipliers. The proposed approach is quite general, a wide class of finite elements of kinematic constraints can be developed with it. Also, method for taking into account friction between joined planes for the “Two-dimensional prismatic joint” FE is proposed. Coulomb friction was considered as a model of friction, however, the proposed approach can be extended to other friction models without significant changes. The developed element with friction can be used, for example, for the dynamic skew modelling in rotors that occurs during operation when friction forces are exceeded.
Experimental study of creep and relaxation of steels at the postcritical stage of deformation
Authors: Tretyakov M P , Feklistova E V , Lykova A V
Published: March 2020

The work is aimed at experimental and theoretical study of the regularities and effects of the behaviour of metallic materials at the stage of postcritical deformation, which is of both applied and fundamental interest from the point of view of understanding preceding of the fracture processes and the possibility of predicting the survivability and kinetics of structural failure processes. An experimental assessment was made of the influence of the strain rate in a wide range on the postcritical behaviour of X15CrNi12-2 steel samples at the temperature of 500 °C. Experimental data of rheological processes of the steel at various levels of achieved postcritical deformation was obtained. It was shown that during creep holding at the postcritical stage of deformation, a transition to the final creep stage and subsequent destruction of the samples almost immediately were occurs. An analysis of the experimental dependences obtained during exposition in the relaxation mode demonstrates the independence of the stress level at the end of exposition on the speed of preliminary deformation and, therefore, on the initial value of the stresses, which reached at the beginning of the exposition. The data obtained are necessary to develop models of softening media, taking into account the rheological processes that occur in metallic materials under conditions of postcritical deformation at high temperatures.
Deformation and failure of polymer composite materials under preliminary cyclic and low-velocity impacts
Authors: Wildemann V E , Staroverov O A , Tretyakov M P
Published: March 2020

The paper presents the results of an experimental study of the behavior of samples of polymer composite materials under complex mechanical loads. A technique has been developed for the experimental assessment of changes in the residual strength and stiffness properties of layered composites for various parameters of preliminary cyclic and low-velocity impacts. Corresponding experimental data were obtained for fiberglass samples with various layouts. In accordance with the considered method for analysis of the obtained data, a fatigue sensitivity diagram has been introduced, which contains the characteristic sections of the change in the residual static strength and its threshold values, and is used to study the processes of damage accumulation and fracture of composites at various loading parameters. The results of a study of the effect of preliminary shock tension on the processes of deformation and fracture of fiberglass samples are presented. As a result of the analysis of the influence of a preliminary three-point impact bending on the mechanical characteristics of fiberglass specimens during tension, a threshold value of impact sensitivity was noted, until which a decrease in the residual strength of fiberglass was not observed. A change in the mechanisms of destruction of the samples under static tension with an increase in the energy of preliminary impact is noted.
Study of the lifetime and lubricity of greases for rolling bearings
Authors: Novikov A V , Prozhega M V , Smirnov N I , Smirnov N N , Nazarov A N
Published: March 2020

This article presents a methodology for the study of the relative lifetime of lubricating greases operating in rolling friction. An experimental assembly is described for testing lubricating greases in order to determine the friction coefficient and relative resource. A criterion for assessing the relative resource of lubricating greases has been proposed. The test results of the proposed method were obtained and presented.
Laser surfacing of copper-based alloys on steel
Authors: Prince A N , Biryukov V P , Savin A P , Starostin D A , Klevetov D V , Bazlova T A
Published: March 2020

The paper presents metallographic studies of samples and the results of tribological tests of coatings. It is shown that the friction coefficients of powder coatings based on copper deposited by a laser beam are 2-3 times lower than those of samples made of bronze rods BrAZh 9-4 and brass L63. The influence of transverse beam oscillations on the quality and performance of the surfacing process is investigated. It is shown that at a beam scanning frequency of 217 Hz, the surfacing performance increases by 1.56-1.7 times
Improving measurement precision and informativity under testing antifrictional materials with Timken machine
Authors: Putintsev S V , Chirsky S P , Pilatskaya S S
Published: March 2020

The expediency of modernization of well-known Timken machine is proved. The way of modernizing Timken machine with a two-lever friction pair loading system is given. The measurement precision and test results informativity under antifriction testing of lubricating and engineering materials are improved. The testing of lubricants using the modernized equipment shows high sensitivity to small changes of mechanical losses, as well as extended informativity of short-term test results.
Experimental and computational determination of hardened zones during laser hardening of steels
Authors: Savin A P , Biryukov V P , Panov D V , Prince A N , Petrovsky V N , Ushakov D V
Published: March 2020

Experiments in defocus of beam rectangular-shaped fiber laser in the range of 30-65 mm. using a full factorial experiment, we constructed the surface to depth and width of the zone of hardening through varying the speed of the beam in the range of 15-20 mm/s, power 3-4 kW. Comparative wear tests have shown that laser hardening with a rectangular spot reduces the number of tempering zones and increases the wear resistance of 40Cr steel by 25-35% compared to hardening with a round spot.
Performance study of electric pump unit bearings of spacecraft thermal control systems
Authors: Smirnov N I , Smirnov N N , Prozhega M V , Matveev S A , Shirobokov O V , Gorbunov A V , Zheltyshev O V
Published: March 2020

This paper presents the methodology and test results of rolling bearings of low-flow electric pump units used to ensure circulation of the thermal liquid in the active thermal control system of spacecraft. A multi-position stand has been developed for testing bearings within 40 days in a thermal liquid at a speed of 6000 rpm with the possibility of registering the separator rate speed. As a performance criterion, the clearance in the bearing is used. The conditions of the onset of pitting are investigated.
Study of the wear resistance of alloyed powder-based hybrid materials manufactured using “KARBUL” technology
Authors: Smirnov N I , Prozhega M V , Smirnov N N , Zelenskay M N , Pyatov I S , Shaposhnikova K V , Ladanov S V
Published: March 2020

This research paper presents the results of studies of the tribological properties of materials manufactured using the “KARBUL” technology, modified with powders of various compositions. The tests were carried out according to the “disk-disk” friction pair on a modern friction machine SMT-1. The structure and wear mechanism of materials manufactured using the Karbul technology have been investigated.