Research on Improvement of Merchant Shear Angle Model

2014 ◽  
Vol 894 ◽  
pp. 192-200 ◽  
Author(s):  
Shu Ting Wang ◽  
Yu Cheng Zhang ◽  
Wei Dong Gou ◽  
Chuan Jiang Liu
Keyword(s):  
Metal Cutting ◽  
Friction Angle ◽  
Calculation Model ◽  
Shear Angle ◽  
Zone Model ◽  
Analysis Model ◽  
Calculation Results ◽  
The Impact ◽  
Angle Calculation ◽  
Key Parameter

Shear angle is a key parameter to characterize the metal cutting. In this paper the Merchant analysis model of shear angle is improved. The impact of shear angle on the shear stress is quantitatively analyzed by using of the unequal division shear zone model and Johnson-Cook constitutive model, and the functional relationship between the tool-chip friction angle and the shear angle is established by Schulz empirical formula. Thus the new shear angle calculation model is established. Calculation results and experiments verify the effectiveness of the improved Merchant model.

Calculation of Wave-Induced Shallow Stratum Seabed Slides in the Subaqueous Yellow River Delta

2009 ◽  
Author(s):  
Guohui Xu ◽  
Xin Wang ◽  
Congcong Wei ◽  
Zibu Fu ◽  
Qingpeng Zhao
Keyword(s):  
Slip Surface ◽  
Yellow River ◽  
Limit Equilibrium ◽  
Yellow River Delta ◽  
Friction Angle ◽  
Calculation Model ◽  
Safety Coefficient ◽  
Wave Flume ◽  
Calculation Results ◽  
Wave Induced

Wave-induced seabed slide could happen even at very gently sloping silty seabed. Based on the wave-seabed interaction, the safety coefficient calculation model of wave-induced gentle seabed slides in the seabed instability was carried out using limit equilibrium method, Bishop Method, in this paper. The calculated results shows that the effective internal cohesion c′ and the effective internal friction angle φ′ affect the location of slip surface and the magnitude of the safety coefficient significantly. The safety coefficient rises linearly with the increases of c′ and φ′ at a fixed depth. The results fit reasonable well with the slide calculation results from a wave flume experiment in laboratory. Additionally, it was concluded that the silty seabed tended to slide under wave actions at the depth less than 5 meters in the Yellow River Subaqueous Delta.

Research on Circumferential Thermal Stress Field of Coke Drum Using ANSYS

2011 ◽  
Vol 71-78 ◽  
pp. 1217-1220
Author(s):  
Rui Tao Zhu
Keyword(s):  
Thermal Stress ◽  
Stress Field ◽  
Temperature Difference ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Indirect Coupling ◽  
Thermal Stress Field ◽  
Calculation Results ◽  
The Impact

The paper takes a realistic coke drum as an example. A finite element analysis model using ANSYS is made, acquired with indirect coupling method, and circumferential thermal stress field of coke drum is calculated. Especially, the boundary conditions are based on the measured data of the realistic coke drum. Then circumferential thermal stress field of coke drum is calculated. The calculation results indicate that the circumferential temperature difference with the same height has little impact to stress of the drum and the circumferential temperature difference has the most important effect on coke drum skirt, so the impact to circumferential cracking of the skirt weld cannot be neglected.

Effect of Temperature Distribution on Critical Speeds of a Dual-Rotor System

2014 ◽  
Vol 709 ◽  
pp. 21-24
Author(s):  
Gui Yu Xin ◽  
Ke Ming Wang ◽  
Mei Jiao Qu ◽  
Tian Yin Wang
Keyword(s):  
High Pressure ◽  
Temperature Distribution ◽  
Critical Speed ◽  
Axial Direction ◽  
Calculation Model ◽  
Rotor System ◽  
Effect Of Temperature ◽  
Critical Speeds ◽  
Calculation Results ◽  
The Impact

A dual-rotor calculation model which can expand freely in the axial direction is established in this paper, and the effects of one-dimensional axial temperature distribution on critical speeds of the dual-rotor system are analyzed with finite element method. The temperature distribution of the dual-rotor system is given referring to that of similar aero-engine rotor system. Assuming that the left end temperature remains at 0 °C, and the highest temperature on the section of the high-pressure turbine disk is 0 °C, 200 °C, 400 °C, 600 °C, and 800 °C respectively, the critical speeds of the dual-rotor system are calculated, analyzed and compared. Calculation results show that, with the increase of the highest temperature of the dual-rotor system, the reduction percentage of the critical speeds increases, and the impact on the first critical speed is most obvious. When the highest temperature is 800 °C, the first critical speed of the rotor system excited by the low-pressure rotor reduces 13.13%, and that excited by the high-pressure rotor reduces 13.49%.

scholarly journals Kinematics and dynamics analysis of new rotary-percussive PDM drilling tool

2021 ◽  
pp. 146134842198915
Author(s):  
Jialin Tian ◽  
Xuehua Hu ◽  
Liming Dai ◽  
Lin Yang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Drill String ◽  
Structure Design ◽  
Drilling Process ◽  
Analysis Model ◽  
Drilling Tool ◽  
Stick Slip ◽  
Rate Of Penetration ◽  
Bottom Hole ◽  
Bottom Hole Assembly ◽  
The Impact

This paper presents a new drilling tool with multidirectional and controllable vibrations for enhancing the drilling rate of penetration and reducing the wellbore friction in complex well structure. Based on the structure design, the working mechanism is analyzed in downhole conditions. Then, combined with the impact theory and the drilling process, the theoretical models including the various impact forces are established. Also, to study the downhole performance, the bottom hole assembly dynamics characteristics in new condition are discussed. Moreover, to study the influence of key parameters on the impact force, the parabolic effect of the tool and the rebound of the drill string were considered, and the kinematics and mechanical properties of the new tool under working conditions were calculated. For the importance of the roller as a vibration generator, the displacement trajectory of the roller under different rotating speed and weight on bit was compared and analyzed. The reliable and accuracy of the theoretical model were verified by comparing the calculation results and experimental test results. The results show that the new design can produce a continuous and stable periodic impact. By adjusting the design parameter matching to the working condition, the bottom hole assembly with the new tool can improve the rate of penetration and reduce the wellbore friction or drilling stick-slip with benign vibration. The analysis model can also be used for a similar method or design just by changing the relative parameters. The research and results can provide references for enhancing drilling efficiency and safe production.

scholarly journals Grill Workers Exposure to Polycyclic Aromatic Hydrocarbons: Levels and Excretion Profiles of the Urinary Biomarkers

2020 ◽  
Vol 18 (1) ◽  
pp. 230
Author(s):  
Marta Oliveira ◽  
Sílvia Capelas ◽  
Cristina Delerue-Matos ◽  
Simone Morais
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Principal Component ◽  
Fold Increase ◽  
Urinary Biomarkers ◽  
Analysis Model ◽  
Exposed Workers ◽  
Polycyclic Aromatic ◽  
The Impact

Grilling activities release large amounts of hazardous pollutants, but information on restaurant grill workers’ exposure to polycyclic aromatic hydrocarbons (PAHs) is almost inexistent. This study assessed the impact of grilling emissions on total workers’ exposure to PAHs by evaluating the concentrations of six urinary biomarkers of exposure (OHPAHs): naphthalene, acenaphthene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene. Individual levels and excretion profiles of urinary OHPAHs were determined during working and nonworking periods. Urinary OHPAHs were quantified by high-performance liquid-chromatography with fluorescence detection. Levels of total OHPAHs (∑OHPAHs) were significantly increased (about nine times; p ≤ 0.001) during working comparatively with nonworking days. Urinary 1-hydroxynaphthalene + 1-hydroxyacenapthene and 2-hydroxyfluorene presented the highest increments (ca. 23- and 6-fold increase, respectively), followed by 1-hydroxyphenanthrene (ca. 2.3 times) and 1-hydroxypyrene (ca. 1.8 times). Additionally, 1-hydroxypyrene levels were higher than the benchmark, 0.5 µmol/mol creatinine, in 5% of exposed workers. Moreover, 3-hydroxybenzo(a)pyrene, biomarker of exposure to carcinogenic PAHs, was detected in 13% of exposed workers. Individual excretion profiles showed a cumulative increase in ∑OHPAHs during consecutive working days. A principal component analysis model partially discriminated workers’ exposure during working and nonworking periods showing the impact of grilling activities. Urinary OHPAHs were increased in grill workers during working days.

scholarly journals Quantifying the Impact of Production Globalization through Application of the Life Cycle Inventory Methodology and Its Influence on Decision Making in Industry

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1271
Author(s):  
Humberto. J. Prado-Galiñanes ◽  
Rosario Domingo
Keyword(s):  
Decision Making ◽  
Carbon Footprint ◽  
Chain Model ◽  
Fundamental Factor ◽  
Supply Chain Model ◽  
The Social ◽  
The Impact ◽  
A Company ◽  
Key Parameter ◽  
Do So

Industries are nowadays not only expected to produce goods and provide services, but also to do this sustainably. What qualifies a company as sustainable implies that its activities must be defined according to the social and ecological responsibilities that are meant to protect the society and the environment in which they operate. From now on, it will be necessary to consider and measure the impact of industrial activities on the environment, and to do so, one key parameter is the carbon footprint. This paper demonstrates the utility of the LCI as a tool for immediate application in industries. Its application shall facilitate decision making in industries while choosing amongst different scenarios to industrialize a certain product with the lowest environmental impact possible. To achieve this, the carbon footprint of a given product was calculated by applying the LCI method to several scenarios that differed from each other only in the supply-chain model. As a result of this LCI calculation, the impact of the globalization of a good’s production was quantified not only financially, but also environmentally. Finally, it was concluded that the LCI/LCA methodology can be considered as a fundamental factor in the new decision-making strategy that sustainable companies must implement while deciding on the business and industrial plan for their new products and services.

Floating Roof Influence on Seismic Response of Large Vertical Storage Tank

2013 ◽  
Vol 671-674 ◽  
pp. 1399-1402
Author(s):  
Ying Sun ◽  
Jian Gang Sun ◽  
Li Fu Cui
Keyword(s):  
Seismic Response ◽  
Storage Tank ◽  
Numerical Solutions ◽  
Fluid Pressure ◽  
Seismic Intensity ◽  
Site Conditions ◽  
Storage Tanks ◽  
Analysis Model ◽  
Base Shear ◽  
The Impact

To study the impact of floating roof on seismic response of vertical storage tank structure system subjected to seismic excitation, select 150000m3 storage tanks as research object, and the finite element analysis model of storage tanks with and without floating roof were established respectively. The seismic response of these two types of structure in different site conditions and seismic intensity were calculated and the numerical solutions were compared. The results show that floating roof has little impact on base shear and base moment in different site conditions and seismic intensity. Floating roof can effectively reduce the sloshing wave height. The influence of floating roof on dynamic fluid pressure decreases with the increase of seismic intensity, which is less affected by ground conditions.

The Mechanical Mechanism Analysis for Mortar Arch Framework Slope Protection Structure

2013 ◽  
Vol 859 ◽  
pp. 143-148
Author(s):  
Yang Xu ◽  
Ding Ling Li ◽  
Li Peng ◽  
Yan Xiao ◽  
Yi Hua Nie
Keyword(s):  
Finite Element Analysis ◽  
Mechanism Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Vertical Loading ◽  
Total Displacement ◽  
The Finite Element Analysis ◽  
Calculation Results ◽  
Real Scale

The finite element analysis model was built as the real scale for mortar arch framework slope protection, and the displacement and strain at different points were collected by vertical loading pressure. So the mechanical mechanism can be studied, and the analysis was done between calculation results and testing results of solid miniature model. The studying results show that the point on the arch foot is the worst stress place for each arch, and the total displacement increase nonlinear as the distance from the slope top increases, and the bump phenomenon exists in the bottom of slope, the points are likely to be broken.

Grinding Force Model for Low-Speed Grinding Based on Impact Principle

2013 ◽  
Vol 797 ◽  
pp. 123-128
Author(s):  
Ming He Liu ◽  
Xiu Ming Zhang ◽  
Shi Chao Xiu
Keyword(s):  
Sliding Friction ◽  
Impact Load ◽  
Grinding Force ◽  
Calculation Model ◽  
Force Model ◽  
Grinding Process ◽  
Low Speed ◽  
Impact Area ◽  
Force Mechanism ◽  
The Impact

In the low-speed grinding process, the force generated when the wheel grinding the workpiece is the result of sliding friction, plough and cutting. While in the actual study, the cutting process has attracted extensive attention. Impact effect to the entire grinding process on the contact is ignored so that the error exists between the calculation grinding force and the measured grinding force. Basing on the shock effect to the grinding process, the paper divides the contact area into impact area and cutting area. And the model of impact load generated from single grit is built. Moreover, the grinding force theoretical calculation model and total grinding force mathematical model is also constructed by analyzing the impact load affecting on the grinding force mechanism. Finally experimental study verifies the correctness of theoretical analysis.

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