scholarly journals SIMULATION MODEL OF THE BRUSH CUTTER ROTOR WITH SIX BLADES

2021 ◽  
Vol 11 (3) ◽  
pp. 121-129
Author(s):  
Mikhail Drapalyuk ◽  
Leonid Bukhtoyarov ◽  
A. Pridvorova
Keyword(s):  
Cutting Forces ◽  
Computer Experiment ◽  
Forest Plantations ◽  
Drive Power ◽  
Virtual Sensors ◽  
Movement Characteristics ◽  
Motion Characteristics ◽  
Working Bodies ◽  
Input Motion ◽  
The Impact

Brush cutters are used in forestry for the care of forest plantations in operations for cutting unwanted tree and shrub vegetation (TSV). Rotors can be used as working bodies. The rotor we are considering is a flywheel, on the outer sides of which the blades are hinged. When cutting DKR with blades, a cutting moment arises, which is transmitted through the knife to the axis of its rotation and then to the shaft driving the flywheel. When designing a brush cutter structure, the impact from the cutting forces of the DKR is decisive for the choice of drive power and rotor parameters. We designed the brush cutter rotor in CAD Solidworks to study the cutting process of the DKR. Its geometric and mass parameters were set; the kinematic links of the links were established. The input motion characteristics were set in the Motion Solidworks module and the cutting moment was applied to the knives. Virtual sensors were installed on the model to record movement characteristics. As a result of a computer experiment for three options, which differ in cutting force and the presence of a damper, the trajectories of the knives and the power consumption of the drive were established

scholarly journals Bubble Sweep-Down of Research Vessels Based on the Coupled Eulerian-Lagrangian Method

2020 ◽  
Vol 8 (12) ◽  
pp. 1040
Author(s):  
Wei Wang ◽  
Guobin Cai ◽  
Yongjie Pang ◽  
Chunyu Guo ◽  
Yang Han ◽  
...  
Keyword(s):  
Pressure Field ◽  
Element Model ◽  
Lagrangian Method ◽  
Discrete Element Model ◽  
Bubble Motion ◽  
Interaction Method ◽  
Movement Characteristics ◽  
Spatial Movement ◽  
Motion Characteristics ◽  
The Impact

To explore the reason for the bubble sweep-down phenomenon of research vessels and its effect on the position of the stern sonar of a research vessel, the use of a fairing was investigated as a defoaming appendage. The separation vortex turbulence model was selected for simulation, and the coupled Eulerian-Lagrangian method was adopted to study the characteristics of the bubble sweep-down motion, captured using a discrete element model. The interaction between the bubbles, water, air, and hull was defined via a multiphase interaction method. The bubble point position and bubble layer were calculated separately. The spatial movement characteristics of the bubbles were extracted from bubble trajectories. It was demonstrated that the bubble sweep-down phenomenon is closely related to the distribution of the bow pressure field and that the bubble motion characteristics is related to the speed and initial bubble position. When the initial bubble position is between the water surface and the ship bottom, the impact on the middle of the ship bottom is greater and increases further with increasing speed. A deflector forces the bubbles to both sides through physical shielding, strengthening the local vortex structure and keeping bubbles away from the middle of the ship bottom.

Investigation of the effect of the constructive and mode parametres of a combined rocker on the power of the drive of the working bodies

2019 ◽  
pp. 82-85
Author(s):  
Pavel Ivanovich Pavlov ◽  
Viktor Vladislavovich Korsak ◽  
Aleksandr Olegovich Vezirov ◽  
Dmitriy Vadimovich Mukhin
Keyword(s):  
Operating Parameters ◽  
Regression Equations ◽  
Drive Power ◽  
Minimum Value ◽  
Working Bodies

The regression equations and graphical dependencies are obtained, which describe the influence of design and operating parameters on the drive power of the working bodies. The value of the design and operating parameters in which the power required to drive the working bodies, will have a minimum value  are experimentally determined.

scholarly journals NECESSITY TO IMPROVE THE MATHEMATICAL MODEL OF FREIGHT CARS TO STUDY CASES OF ITS DERAILMENTS

2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Computer Experiment ◽  
Rolling Stock ◽  
Software Systems ◽  
Freight Car ◽  
The Stability ◽  
The Many ◽  
The Impact ◽  
The Mathematical Model

One of the most important problems that pose a serious threat to the functioning of railways is the problem of freight cars derailment. However, according to statistics, the number of cases of the derailments of freight cars in trains annually grows. Тo prevent such cases, the necessary preventive measures are developed, and to study the causes of their occurrence, a significant number of mathematical models, programs and software systems created by leading domestic and foreign scientists. Studies of such mathematical models by the authors of this work have led to the conclusion that they are not sufficiently detailed to the extent that it is necessary for analyze the reasons of its derailment. At the same time, an analysis of the causes of the rolling stock derailments on the railways of Ukraine over the past five years showed that in about 20 % of cases they are obvious, and in 7 % of cases they are not obvious and implicitly expressed. The study of such cases of rolling stock derailment during an official investigation by the railway and during forensic railway transport expertises requires the use of an improved mathematical model of a freight car, which would allow a quantitative assessment of the impact of its parameters and rail track on the conditions of railway accidents. Therefore, taking into account the main reasons that caused the occurrence of such railroad accidents over the last five years on the railways of Ukraine, the article selected the main directions for improving the mathematical model of a freight car, allowing to cover all the many factors (explicit and hidden) and identify the most significant ones regarding the circumstances of the derailment rolling stock off the track, established on the basis of a computer experiment. It is proposed in the mathematical model of a freight car to take into account the guiding force, the value of which is one of the main indicators of the stability of the rolling stock. The authors of the article noted that not taking into account the influence of the guiding forces on the dynamics of the freight car can lead to an erroneous determination of the reasons for the rolling stock derailment or even to the impossibility of establishing them.

scholarly journals To Trust Or Not To Trust: The Impact Of WebTrust On The Perceived Trustworthiness Of A Web Site

2001 ◽  
Vol 5 (3) ◽  
pp. 35-50 ◽  
Author(s):  
Kris Portz ◽  
Joel M. Strong ◽  
Larry Sundby
Keyword(s):  
Electronic Commerce ◽  
Web Sites ◽  
Private Information ◽  
Web Site ◽  
Positive Impact ◽  
Computer Experiment ◽  
The Internet ◽  
Certified Public Accountants ◽  
Assurance Services ◽  
The Impact

Despite the explosive growth of electronic commerce, many individuals are still reluc-tant to conduct business transactions on the Internet. Individuals may mistrust sending private information over the Internet or they may have concerns about the existence, performance, standing, and integrity of online businesses. In direct response to these concerns, the American Institute of Certified Public Accountants (AICPA) has developed an electronic commerce assurance service called WebTrust which is intended to improve the consumer's confidence in the process and the quality of information disclosed on vendor web sites. The purpose of this study is to shed light on the effectiveness of WebTrust by examining the influence of WebTrust on consumers' perceptions of a web site's trustworthiness. The question is investigated through a computer experiment. The results of this study are very encouraging for electronic commerce assurance services in general, and the WebTrust service in particular. Evidence is found that the presence of WebTrust on a web site has a positive impact on the perceived trustworthiness of the website. The results also show that knowledge of WebTrust plays a significant moderating role in the relationship between perceived trustworthiness and the presence of WebTrust. When subjects have prior knowledge of WebTrust they perceive a web site with WebTrust to be more trustworthy than a web site without whereas, the presence of WebTrust has no impact when subjects are uneducated about the WebTrust assurances. Also, when WebTrust is present, subjects with knowledge of WebTrust are more confident in the web site than those without knowledge of WebTrust. When WebTrust is not present, knowledge subjects are more unsure of a web site without WebTrust than those without knowledge.

The Design of Mechanical Grates Experimental Device of Municipal Solid Waste

2012 ◽  
Vol 233 ◽  
pp. 311-315
Author(s):  
Xin Cai Zhu ◽  
Peng Li ◽  
Lei Guo ◽  
You Qing Ding ◽  
Shun Hong Lin
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Experimental Device ◽  
Structure Parameters ◽  
Strong Basis ◽  
Stop Time ◽  
Movement Characteristics ◽  
Push Forward ◽  
Move Distance ◽  
The Impact

In order to research the impact of the structure parameters of mechanical grate on MSW(Municipal Solid Waste) movement characteristics such as transportation speed, average stop time and mixed rate of waste, a kind of mechanical grate cold experimental device has been designed. This device can realize the switch between push forward and backward. Many structure parameters can be adjusted such as the height of grate, move distance of grate, bed angle, and move speed of the grate. Based on Mechanical grate cold experimental device, to study the impact of the mechanical grate structure parameters on the characteristics of waste movement is conducive to applying the results of test to the actual MSW grate incinerator. It provides a strong basis for the improvement and optimization of the mechanical grate furnace in terms of characteristics of Chinese MSW.

Effects of Seismic Incident Directionality on Ground Motion Characteristics and Responses of a Single-Mass Bi-Degree-of-Freedom System

2021 ◽  
pp. 2150119
Author(s):  
Jun Gong ◽  
Xudong Zhi ◽  
Feng Fan ◽  
Shizhao Shen ◽  
Da Qaio ◽  
...  
Keyword(s):  
Ground Motion ◽  
Large Scale ◽  
Seismic Analysis ◽  
Ground Motions ◽  
Propagation Distance ◽  
Degree Of Freedom ◽  
Different Types ◽  
Single Mass ◽  
Motion Characteristics ◽  
The Impact

To investigate the variability of ground motion characteristics (GMC) with the angle of seismic incidence (ASI) and the impact of seismic incident directionality on structural responses, first, a large-scale database of recorded ground motions was used to analyze the causes of GMC variability due to the seismic incident directionality effect (SIDE). Then a single-mass bi-degree-of-freedom system (SM-BDOF-S) with different types of symmetrical sections was selected to explore the influence mechanism of SIDE on the seismic responses. The results illustrated that the GMC has substantial variability with the ASI, which is independent of the earthquake source, propagation distance, and site condition, and exhibits complex random characteristics. Additionally, a classification method for ground motions is proposed based on this GMC variability to establish a criterion for selecting ground motions in seismic analysis considering the SIDE. Moreover, for an SM-BDOF-S, the response spectral plane is proposed to explain the transition behavior of spectral responses that are very similar among different stiffness ratios, but divergent for different types of ground motions. The influence of SIDE on structures is determined by their stiffness and stiffness ratio in the [Formula: see text]- and [Formula: see text]-directions, as well as the type of ground motion.

Study of a Two-section Mixer for the Preparation of Balanced Mixtures on Cattle Farms

2020 ◽  
pp. 107-113
Author(s):  
Ruslan Kisilyov ◽  
◽  
Vasil Khmelevsky ◽  
Petro Luzan ◽  
Iryna Sysolina ◽  
...  
Keyword(s):  
Mutual Influence ◽  
Full Range ◽  
High Energy ◽  
Drive Power ◽  
Feed Processing ◽  
Processing Technologies ◽  
Basic Parameters ◽  
Specific Material ◽  
Working Bodies ◽  
Quality Process

Improving of livestock industry efficiency significantly depends on quality of feed preparation, as they are in cost structure of products are 30-60% of costs. Advanced technologies that allow to fully realize genetic potential of animals, due to the lack of necessary technical support have not become widespread. The experience of using intensive full-system technologies for livestock production shows that, along with reliable and balanced provision of farms with high quality feeds, traditional feeding systems are being improved, which are aimed at the development of economically efficient mechanized feed processing technologies and the preparation of full-range and balanced feed mixtures. Existing designs of feed mixers for cattle do not fully meet the zootechnical requirements for the preparation of multicomponent balanced complete feed mixtures, have high energy costs and high specific material consumption. Therefore, research aimed at developing working bodies for feed mixers, which will ensure the creation of a highly efficient feed base at low energy and material costs are of economic importance and is an urgent scientific task. In the article on the basis of the conducted researches the basic constructive-technological scheme of the effective single-shaft two-section mixer for realization of process of preparation of balanced mixes for cattle executed in the form of the horizontally located cylindrical case with the combined mixer consisting of section of screw tapes and flat blades (left and right) direction of inclination, the working surface of which is located at an angle of 45… 500 to the axis of the shaft and is equipped with radial fingers. The purpose of experimental research was to establish identification of developed mathematical models and adequacy of research results of proposed feed mixer and determine impact of basic parameters and modes of its operation on quality process. Аchieve this goal, mutual influence of simultaneous changes in speed of agitator shaft, width of flat blade angle of blade to axis of agitator shaft and duration of feed mixing on quality process: homogeneity of mixture and drive power of mixer shaft. Theoretical studies of the process of preparation of a balanced complete ration mixture confirmed the advantage of the developed design of the combined two-section mixer and increased the quality index (homogeneity of the mixture) to 98%

Predictive Modeling and Optimization of Cutting Forces Through RSM and Taguchi Techniques in the Turning of ASTM B574 (Hastelloy C-22)

2018 ◽  
pp. 398-417
Author(s):  
İsmail Kırbaş ◽  
Musa Peker ◽  
Gültekin Basmacı ◽  
Mustafa Ay
Keyword(s):  
Feed Rate ◽  
Cutting Forces ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Orthogonal Experimental Design ◽  
Depth Of Cut ◽  
Effective Parameters ◽  
Factors Affecting ◽  
The Impact

In this chapter, the impact of cutting parameters (depth of cut, cutting speed, feed, flow, rake angle, lead angle) on cutting forces in the turning process with regard to ASTM B574 (Hastelloy C-22) material has been investigated. Variance analysis has been applied in order to determine the factors affecting the cutting forces. The optimization of the parameters affecting the surface roughness has been obtained using response surface methodology (RSM) based on the Taguchi orthogonal experimental design. The accuracy of the developed models required for the estimation of the force values (Fx, Fy, Fz) is quite successful. In this study, where the R2 value has been used as the criterion/measure, accuracy values of 93.35%, 95.03%, and 95.09% have been achieved for Fx, Fy, and Fz, respectively. As a result of the ANOVA analysis, the most effective parameters for Fx at a 95% confidence interval are depth of cut, feed rate, flow, and rake angle. The most effective parameter for Fy is depth of cut, while the most effective parameters for Fz are depth of cut, feed rate, and flow, respectively.

Predictive Equations to Quantify the Impact of Spectral Matching on Ground Motion Characteristics

2016 ◽  
Vol 32 (1) ◽  
pp. 125-142 ◽  
Author(s):  
Clinton Carlson ◽  
Dimitrios Zekkos ◽  
Adda Athanasopoulos-Zekkos
Keyword(s):  
Ground Motion ◽  
Response Spectrum ◽  
Time History ◽  
Peak Ground Velocity ◽  
Spectral Matching ◽  
Predictive Equations ◽  
Earthquake Scenarios ◽  
Cumulative Absolute Velocity ◽  
Motion Characteristics ◽  
The Impact

Spectral matching, the process of modifying a seed acceleration time history in intensity and frequency content until its acceleration response spectrum matches a target spectrum, is used extensively in practice. Predictive equations that quantify the impact of spectral matching on the peak ground velocity, peak ground displacement, Arias intensity, and cumulative absolute velocity of a scaled seed time history have been developed and validated on the basis of thousands of matched motions, three different earthquake scenarios, and numerous target spectra. It is found that spectral mismatch is the most critical factor affecting the changes in ground motion characteristics. The technique used for modification (e.g., time domain or frequency domain) is in many cases not critical. Based on the results, recommendations in order to minimize the impact of matching on the ground motion characteristics are provided.

A Data Cooperative Caching Policy Using Human Mobile Patterns for Delay Tolerant Networks

2010 ◽  
Vol 171-172 ◽  
pp. 561-564
Author(s):  
Hui Ye ◽  
Zhi Gang Chen ◽  
Xiao Jian Shen
Keyword(s):  
Network Performance ◽  
Data Dissemination ◽  
Delay Tolerant Networks ◽  
Cooperative Caching ◽  
Network Cost ◽  
Movement Characteristics ◽  
Delay Tolerant ◽  
The Impact ◽  
Caching Policy ◽  
Address Matching

Recently, many researchers focus on delay tolerant networks (DTN). In DTN, the mobile characteristic of nodes is used to help transfer data. Therefore, how to use the cooperative relations and cache resource of nodes effectively to avoid network congestion and improve network performance is an important issue. In this paper, we proposed a cooperative caching policy based on human mobile patterns, which referred as HMP-Cache. The node movement characteristics are discussed in detail in HMP-Cache. HMP-Cache uses the standard of target address matching to choose cooperative caching nodes. In addition, the sharing caching information is done by synchronization of caching table in local region. Therefore, the impact of useless data dissemination of multiple hops is reduced. And the shortcoming of limited caching resources is compensated. The simulation results show that our policy can control the network cost effectively. Also, the remote data latency is reduced.

Sign in / Sign up

Export Citation Format

Share Document