scholarly journals Influencing Factors of Void closure in Skew-Rolled Steel Balls Based on the Floating-Pressure Method

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1391
Author(s):  
Chang Shu ◽  
Jitai Wang ◽  
Xuedao Shu ◽  
Duanyang Tian
Keyword(s):  
Numerical Analysis ◽  
Influencing Factors ◽  
Influencing Factor ◽  
Uniform Design ◽  
Metal Flow ◽  
Rolled Steel ◽  
Void Closure ◽  
Pressure Method ◽  
Steel Balls ◽  
Skew Rolling

Due to the instable conditions caused by the wear of rollers, macro voids inevitably occur in skew rolling steel balls. Macro voids in rolled balls greatly weakens the mechanical properties, resulting in the scrapping of about 23% of all skew rolling balls. This paper adopts the floating-pressure method (FPM) to eliminate macro voids in rolled steel balls, and mainly focuses on the investigation of the influencing factor void closure in skew-rolled balls. The research contents are listed as follows: Firstly, the mechanical model of FPM eliminating void in rolled steel balls is established, and the theoretical relationship between influencing factors of void closure is obtained. Then, the metal flow behaviors, the stress distribution and the effect of process parameters on void closure are revealed by numerical analysis. Subsequently, based on the uniform design method, the prediction equation of the required temperature and air pressure for compacting various inferior rolled balls with different diameter by FPM is deduced. Finally, the FPM experiment is carried out to verify the results of numerical analysis. The research results provide theoretical guidance for eliminating macro voids in skew-rolled steel balls.

Sensitivity Analysis on Influencing Factors of Double-Row Piles for Excavation

2013 ◽  
Vol 671-674 ◽  
pp. 290-295
Author(s):  
Kai Yu Jiang ◽  
Jing Cao ◽  
Hai Ming Liu ◽  
Hui Min Zhao
Keyword(s):  
Sensitivity Analysis ◽  
Influencing Factors ◽  
Influence Factor ◽  
Influencing Factor ◽  
Uniform Design ◽  
Horizontal Displacement ◽  
Geological Condition ◽  
Double Row ◽  
Equivalent Thickness ◽  
Space Length

Sensitivity analysis of double-row piles is often obtained by changing the value of single influencing factor and doesn’t considering the interaction of influencing factors. So, a new sensitivity analysis method is proposed which can consider the interaction of influencing factors. In this method, uniform design (UD) and alternating conditional expectations regression (ACE) are used. The embedded depth of the forward pile, row space, length of the back pile, equivalent thickness of forward pile, equivalent thickness of coupling beam, and equivalent thickness of back pile are six input parameters called influencing factors. The maximum horizontal displacement of the pile head (MDP), maximum bending moment of forward pile (MMF), maximum ground settlement (GS), and coefficient of global stabilization (CGS) are four outputs as target parameters. The sensitivity can be obtained in this geological condition, excavation depth and surrounding environment. It is showed that the stiffness of back pile is the critical influence factor to MDP, the stiffness of forward pile is the critical influence factor to MMF and GS, and the length of back pile is the critical influence factor to CGS.

scholarly journals The Chosen Aspects of Skew Rolling of Hollow Stepped Shafts

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 764
Author(s):  
Jarosław Bartnicki ◽  
Yingxiang Xia ◽  
Xuedao Shu
Keyword(s):  
Cross Section ◽  
Rolling Mill ◽  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Numerical Control ◽  
Technological Parameters ◽  
Flow Mechanisms ◽  
The Individual ◽  
Skew Rolling

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.

scholarly journals The Effect of Process Parameters in Helical Rolling of Balls on the Quality of Products and the Forming Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak
Keyword(s):  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Helical Rolling ◽  
Forming Process ◽  
University Of Technology ◽  
Quality Of Products ◽  
Skew Rolling

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.

scholarly journals Combined experimental and numerical analysis of a bubbly liquid metal flow

2017 ◽  
Vol 228 ◽  
pp. 012006 ◽  
Author(s):  
B Krull ◽  
E Strumpf ◽  
O Keplinger ◽  
N Shevchenko ◽  
J Fröhlich ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Liquid Metal ◽  
Metal Flow ◽  
Bubbly Liquid ◽  
Liquid Metal Flow

scholarly journals Extracting relationship between air pollution and precipitation using spatio-temporal analysis in Tehran metropolis

2019 ◽  
Vol 2 ◽  
pp. 1-7
Author(s):  
Shokouh Dareshiri ◽  
Mohammadreza Sahelgozin ◽  
Maryam Lotfian ◽  
Jens Ingensand
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Regression Model ◽  
Influencing Factors ◽  
Polynomial Regression ◽  
Human Life ◽  
Pearson Correlation ◽  
Influencing Factor ◽  
Polynomial Equation ◽  
Temporal Analysis

<p><strong>Abstract.</strong> Precipitation is one of the main stages of the water cycle, and it is required for the organisms to survive on the planet. In contrast, air pollution is a phenomenon that has greatly affected the human life nowadays. Population growth, development of factories and increasing number of fossil fuel vehicles are the most influencing factors on air pollution. In addition to understand nature of precipitation and air pollution, finding relationship between these two phenomena is necessary to make appropriate policies for reducing air pollution. Furthermore, studying trends of precipitation and air pollution in the past, is helpful to forecast the times and places with less precipitation and more air pollution for a better urban management. In this study, we tried to extract any probable relationship between these two parameters by investigating their monthly measured amounts in 22 municipal districts of Tehran in three epochs of time (2009, 2013 and 2017). Carbon Monoxide (CO) was considered as the indicator of air pollution. Results of the study show that the parameters have a significant relationship with each other. By using Pearson Correlation Coefficient and One-Way Variance (ANOVA) test, relationship between the data for each month and for each district of Tehran were studied separately. As the time has passed and the air pollution has increased, the correlation between the parameters in districts has decreased. In addition, during the cold months of the year, the correlations decrease since the fact that precipitation is not the only influencing factor on the air pollution due to the rise of air “Inversion”. Finally, the polynomial regression model of carbon monoxide based on precipitation was extracted for each of the three years. The model suggests a degree three polynomial equation. The obtained coefficients from the regression model show that the relationship between parameters was stronger in the years with more rainfalls. This can be due to the more significant impact of other influencing factors on air pollution, such as population density, wind direction, vehicles and factories in the areas or conditions with a less rainfall.</p>

scholarly journals Analysis of Revenue Incentive Dynamic Mechanism of Financial Supply Chain from the Perspective of the Internet of Things

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yue Yin
Keyword(s):  
Supply Chain ◽  
Life Cycle ◽  
Influencing Factors ◽  
Incentive Mechanism ◽  
Influencing Factor ◽  
Blockchain Technology ◽  
Supply Chain Finance ◽  
The Incentive Mechanism ◽  
Relationship Factors ◽  
The Internet Of Things

With the rapid development of society, all walks of life need the support of the Internet of Things, and the financial industry is no exception. This article integrates blockchain technology with supply chain finance and builds a supply chain financial alliance architecture based on blockchain technology and an underlying model of the Ethereum blockchain system suitable for supply chain finance. We innovated new supply chain finance models and operating mechanisms and proposed business scenarios for supply chain finance from the perspective of blockchain. Taking into account the actual operation of the blockchain supply chain financial platform, the principal-agent model and the incentive theory are applied, and the supply chain financial accounts receivable model is taken as an example in the case of complete information and incomplete information. The incentive mechanism between the service provider of the chain supply chain financial platform and the core enterprise promotes the better implementation of blockchain technology and supply chain finance. Based on the existing theoretical research, this paper identifies the key influencing factors of the supply chain’s cross-enterprise incentive mechanism. These influencing factors system includes two dimensions: transaction factors and relationship factors. Transaction factors include resource dependence, uncertainty, and cooperation experience; relationship factors include corporate reputation, trust level, and relationship commitment. Based on the nature of the incentive mechanism, information sharing and revenue sharing are extracted as the measurement dimensions of the supply chain’s cross-enterprise incentive mechanism. On this basis, this article draws on the existing enterprise life cycle division method and constructs a hypothetical model of the influencing factors of the incentive mechanism in the incubation period, the growth period, and the maturity period. Relevant data was collected through questionnaires, and SPSS and AMOS software were used to perform statistical analysis, reliability analysis, exploratory factor analysis, confirmatory factor analysis, and structural equation hypothesis testing on the data. The performance of each influencing factor in different stages of the enterprise’s life cycle and the importance of each influencing factor in the same life cycle stage are obtained.

A Study on the Effectiveness of College English Blended Learning Under MOOCs Philosophy in China

2020 ◽  
pp. 247-270
Author(s):  
Zhaohui Dai
Keyword(s):  
Collaborative Learning ◽  
Blended Learning ◽  
Influencing Factors ◽  
Influencing Factor ◽  
Negative Attitude ◽  
Great Emphasis ◽  
Autonomous Learning ◽  
College English ◽  
Blended Education ◽  
Attitude And Motivation

This study investigated the effectiveness of college English blended education under MOOCs philosophy in China. The findings suggest that many features of MOOCs philosophy are evident in college English blended education and eight factors influence effectiveness. Relationships of the influencing factors demonstrate that interactions and evaluations are highly influencing factors in autonomous learning and motivations exert high influences on autonomous learning. However, students have low motivation in interaction and evaluation, for they are more extrinsically than intrinsically motivated. And also, collaborative learning is the least influencing factor in the study. To motivate the students, great emphasis should be laid on interactions and evaluation in student's autonomous learning. Moreover, students' negative attitude towards autonomous learning hampers their adaptability to college English blended learning, and, as attitude and motivation are highly related, this deserves equal attention.

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